K&N = Engine Check Light?

[JAFO]

Last night I installed a K&N stock replacement air filter and PIAA Xtreme White Plus headlights.

This morning the engine check light was on during my drive to work. My VX has just rolled over the 70K mile mark.

Could the K&N filter trip the check engine light or could this be a "Time for Servicing" alert based upon mileage?

[JAFO]

I talked with the dealership and they said that there is no mileage check that would trip the engine check light.

They said that either it is a emission check problem. Which they said to check the gas cap.

Or they said that they have had problems with the oil from the K&N air filter messing up the Mass Air Flow (MAF) sensor.

Has any body else had this problem with the K&N filters?

[JULIAN911]

I had the drop-in K&N filter and now a huge cone filter after the SC installed - no check engine light. You may want to disconnect the battery and let the ECM reset to adjust to higher airflow.

[mbeach]

I've been running K&Ns for awhile now -no CELs.

Can you take take it to an AutoZone/Shucks/Kragen/Advance and get it scanned?

[Numba1goalie]

I just put a K&N and I have 62k on mine. It works fine. I also took off the little elbow that goes with it.

Still get bad gas milage though.

[JAFO]

I had the drop-in K&N filter and now a huge cone filter after the SC installed - no check engine light. You may want to disconnect the battery and let the ECM reset to adjust to higher airflow.

Just tried that. When I restarted the VX it surges continuosly now. Until I press the accelerator to even it out. When I let off it continues to surge the throttle and then the engine check light comes on and then it levels out the RPMs.

I took out the K&N filter, put the stock one back in, and disconnected the battery again. When I started it back up it repeated the same thing.


Can you take take it to an AutoZone/Shucks/Kragen/Advance and get it scanned?

I'm going to take it there right now.

[VehiX]

Did you damage the MAF screen or the thin wire behind it or loosen a connection on the MAF when switching out the filter? Sounds like a possible cause. Getting the filter around the intake tube can be tricky because it's a tight fit some times and the screen and harness are right there when you're working on it. Any performace changes now that the light's on? If so I would check these two possiblities.

[JAFO]

Did you damage the MAF screen or the thin wire behind it or loosen a connection on the MAF when switching out the filter? Sounds like a possible cause. Getting the filter around the intake tube can be tricky because it's a tight fit some times and the screen and harness are right there when you're working on it. Any performace changes now that the light's on? If so I would check these two possiblities.

I took off the top of the air cleaner housing last night when I was changing the light bulbs. I disconnected it on the first clamp on the air box side. I did not disconnect the MAF sensor. I could have dumped something out of place. It is on snug but is possible that it is not on perfectly.

Yes it doesn't seam to be running the same and it actually stalled at a stop light. Not a big deal but it did take me 10 seconds to realize that I couldn't restart it because it was still in drive. Damn automatics.

AutoZone checked the code. It is reading low input from the MAF sensor. They said it happens a lot. He sold me some electronics cleaner and said to remove the MAFS and clean it out really good. He then suggested that I take an air compressor and blow out the K&N to remove excess oil from the filter. Although I didn't oil it, it came preoiled.

I'm going to try this after work.

[mbeach]

Be careful using compressed air on the K&N -the high pressure will tear the cotton gauze and you'll end up with a hole.

Your symptoms sound a lot like those experienced with torn intake manifold gaskets -after you've run through the standard MAF sensor cleaning, give those a look.

[alleycat]

Where is this MAF sensor. Out of the clear blue my check engine lite has come on also. Code is reading lean 1st bank [171]. Checked gas cap, cleared code 3 times and lite still coming on. It is running pretty good and a little rough idle now and them. Could there be a blown fuse somewhere that would make this engine lite come on?

[JAFO]

Be careful using compressed air on the K&N -the high pressure will tear the cotton gauze and you'll end up with a hole.

Your symptoms sound a lot like those experienced with torn intake manifold gaskets -after you've run through the standard MAF sensor cleaning, give those a look.

mbeach, Where is the intake manifold gaskets?

I have completely removed the intake tube, with the MAF. I couldnt figure out how to get the MAF out of the tube though. It was still stuck even after removing the clamp. I didn't pry the tube because I didn't want to damage it.

I heavily sprayed the inside of the mesh screen with electronics cleaner that they sold me at AutoZone. I have the original air filter back in and I disconnected the battery twice. But it is still surging on startup then the engine check light comes on and the RPMs level out.

Also when I drove the truck home, approximately 3 miles, it died twice.

I looked and as best I can tell the little wires on the MAF behind the mesh look ok.

Also what is the little sensor on the oposite side end of the tube next to the intake? O2 sensor?

[mbeach]

I'm not going outside to check right now (it's about -40), but there's no O2 sensor on the intake, I can't picture what you're talking about. I'll look it up later.

The intake manifold is under the plastic cover on the top of the engine. Where the manifold meets the heads (on both sides) there is a gasket that you may or may not see.
Start the truck and spray some carb cleaner along this area -just a dusting, not soaking it down. If the engine surges, then you have a leak -the engine's vacuum is drawing the carb cleaner into the cylinders through the torn gasket.

The purpose of the MAF is to determine how much air is entering the engine. If there is a leak post-MAF, then the air measured is not what is actually entering the cylinders. This will lean out your air/fuel ratio and throw off your O2 sensors. The only component that the OBD can reference is the MAF -so it throws a MAF code even though the problem might be elsewhere.

[Raque Thomas]

Are you certain that the MAF sensor wiring harness is hooked up? Mine did this same thing when I unplugged the connection to get more slack in the tube when installing a new filter. Could the plug be what you think is an O2 sensor?

I also ran an oiled K&N with no CEL, and now a Hot Shot tube with an oiled cone filter w/o a CEL. I'm betting your connection is the problem. If the harness is connected to the side of the MAF, disconnect it and check the condition of the connectors, then try plugging it back in.

[psychos2]

if it is gettting a code for the maf then that is the problem. not the intake gaskets.either a wire is pulled out or a bent prong or it is dirty or covered in oil.the other sensor is more than likely an air temp sensor. shawn

[mbeach]

if it is gettting a code for the maf then that is the problem. not the intake gaskets.

Not necessarily.
The engine only has one way of determining the correct a/f ratio before the burn -that's the MAF. After the burn you have 2/4 O2 sensors.

If there's a leak (air) between these sensors, the ECU can pick the most likely item. It finds the fault at the O2 sensorS (all of them). Since it is unlikely that both banks would simultaneously go lean, the ECU has the sense to choose the component which measures the incoming air to begin with.

Disconnect the intake tube from the throttle body and I'll bet that you throw a MAF code.

[JAFO]

Ok, I have found what happened. While I was installing the headlights, before I put in the K&N, I had the cover off the air box but not disconnected from the MAF or tube. I had pushed the air box cover towards the dash and hooked it over the top of the fuid bottle next to the air box to get it out of my way while installing the headlights. I think this is the power steering bottle, I don't recall. Any ways when I did this I was not as carefull as I should have been and it put too much tension on the cable going to the MAF. Upon close examination of the MAF plug I noticed that one of the wires was loose. It actually broke the wire where the pin was crimped on.

Unfortunetly nobody in town as either the right 3-pin replacement plug or wire terminals small enough to fit. So I am going to have to wait until Monday to order a new plug or pin.

[mbeach]

I'm glad that you found the problem.

[JAFO]

Fixed it. I was able to remove the wire terminal and resolder the wire back on.

I put the K&N bask in and no engine check light. I took it for a spin and I can tell the difference. Under accelleration the engine even sounds smoother.

Thanks for all of your help!

BTW, Now that it's dark I'm going to go try out my new PIAA Xtreme White headlights.

[psychos2]

Not necessarily.
The engine only has one way of determining the correct a/f ratio before the burn -that's the MAF. After the burn you have 2/4 O2 sensors.

If there's a leak (air) between these sensors, the ECU can pick the most likely item. It finds the fault at the O2 sensorS (all of them). Since it is unlikely that both banks would simultaneously go lean, the ECU has the sense to choose the component which measures the incoming air to begin with.

Disconnect the intake tube from the throttle body and I'll bet that you throw a MAF code.
sorry, but that is not how it works.the computer has parameters and when it is outside the parameters it throws a code for that sensor.and the maf is not the only sensor it uses to determine a/f ratio. it also uses the air temp sensor . i agree you would get a check engine light if you disconnect the intake tube but it would not be because it picks the most likely sensor. it would be because it knows there is oxygen coming in (engine cannot run without it) but it is not getting a reading from the maf saying there is air coming in. and you would more than likely get other codes due to the maf not showing air coming in. besides when something is functioning properly before you install something and is not working properly after there is a very big chance (probably 99.9%) that you screwed something up. like pulling the wire to hard. when diagnosing problems you start with the simplest things first. shawn

[mbeach]

If you read my first post, you'll notice that I said to give the intake manifold gaskets a look AFTER you're done with the MAF.

IAT sensor just helps the ECU determine air density (based on temp.). Unmetered air entering the engine (and being detected post-burn) will always point to the MAF. The intake gasket leaks are usually intermittent enough that they won't throw a code before driveability suffers. In fact, both of my trucks sprung leaks at the intake gaskets without a code at all.

If you rely solely on CELs to diagnose problems you're in for some long nights. Check the obvious, like you said, then check the likely.
If he had ruled out the MAF (could've just checked for continuity at the engine side of the sensor), where should he go next?

Having spent a number of years behind the wheel of a tuned scooby, I learned that CELs are only a guide, and not the be-all-end-all of engine diagnostics. Your statement "...if getting a code for the MAF then that is the problem..." smacks of finality, and will lead to headaches if you start replacing sensors unnecessarily.

[psychos2]

Your symptoms sound a lot like those experienced with torn intake manifold gaskets -after you've run through the standard MAF sensor cleaning, give those a look.

You mean the above post. Which is not the same as what you just said in your last post . Read your post again. Just cleaning does not rule out the MAF sensor.
If you read what I said " If it is gettting a code for the MAF then that is the problem. Not the intake gaskets. Either a wire is pulled out or a bent prong or it is dirty or covered in oil." And from another post " Besides when something is functioning properly before you install something and is not working properly after there is a very big chance (probably 99.9%) that you screwed something up. Like pulling the wire to hard. When diagnosing problems you start with the simplest things first." You check the things you may have messed up. If he had followed your suggestion he would have been changing the intake gaskets or paying someone to do it and would still have the problem.A broken wire on the plug. You need to rule out all the possible problems with the maf sensor not just cleaning it. And a quote from another of your posts. " If you rely solely on CELs to diagnose problems you're in for some long nights. Check the obvious, like you said, then check the likely.
If he had ruled out the MAF (could've just checked for continuity at the engine side of the sensor), where should he go next? " Well, after cleaning and checking for broken wires or continuity, he would have found the problem. Like I said before " Besides when something is functioning properly before you install something and is not working properly after there is a very big chance (probably 99.9%) that you screwed something up. Like pulling the wire to hard. " In other words the simplest things to check are the things you may have screwed up. I am not trying to argue I just do not like to see people pushed in the wrong direction. You have also said yourself that you did not get any code with the intake gasket leak.Well neither did I when I had a leak. So knowing what you and I both know, I would not guess the intake gasket. Shawn

[mbeach]

I should have typed "...after CHECKING your MAF..." instead of "cleaning" -I was most likely sitting at my desk bitching about the cleaning lady and it just stuck in my head.

I don't like to see people pushed in the wrong direction either -I also don't like to see them pushed into just one direction. If everyone had only one answer, we sure would miss alot.

Your posts are really difficult to read -consider troubleshooting your 'shift' key.

[psychos2]

You mean the above post. Which is not the same as what you just said in your last post . Read your post again. Just cleaning does not rule out the MAF sensor.
If you read what I said " If it is gettting a code for the MAF then that is the problem. Not the intake gaskets. Either a wire is pulled out or a bent prong or it is dirty or covered in oil." And from another post " Besides when something is functioning properly before you install something and is not working properly after there is a very big chance (probably 99.9%) that you screwed something up. Like pulling the wire to hard. When diagnosing problems you start with the simplest things first." You check the things you may have messed up. If he had followed your suggestion he would have been changing the intake gaskets or paying someone to do it and would still have the problem.A broken wire on the plug. You need to rule out all the possible problems with the maf sensor not just cleaning it. And a quote from another of your posts. " If you rely solely on CELs to diagnose problems you're in for some long nights. Check the obvious, like you said, then check the likely.
If he had ruled out the MAF (could've just checked for continuity at the engine side of the sensor), where should he go next? " Well, after cleaning and checking for broken wires or continuity, he would have found the problem. Like I said before " Besides when something is functioning properly before you install something and is not working properly after there is a very big chance (probably 99.9%) that you screwed something up. Like pulling the wire to hard. " In other words the simplest things to check are the things you may have screwed up. I am not trying to argue I just do not like to see people pushed in the wrong direction. You have also said yourself that you did not get any code with the intake gasket leak.Well neither did I when I had a leak. So knowing what you and I both know, I would not guess the intake gasket. Shawn


Is that better. My SHIFT key works just fine. Why would you move on to the next step before completing the first? Have you ever seen a diagnostic chart?If you do not check all the things in the proper order you will never find the problem! Did I mention that I deal with this stuff at work. I have been a MECHANIC for many years. Shawn

[whtzmbi]

I just installed a K&N filter with no problem...the CEL has not come on at all (yet) I hope it doesn't either :)

[JAFO]

I just installed a K&N filter with no problem...the CEL has not come on at all (yet) I hope it doesn't either :)

You should be good. My problem was I wasn't carefull with the MAF wire under the intake tube and pulled the wire loose.

Now that the K&N is in I have been contemplating exhaust change. But I can't till my RX-7 is back from getting turboed.