Posted this over at RennTech as well but figured some members here could maybe point me in the right direction as well...

Thanks in Advance!

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Hello All...

I have searched and read all questions and responses regarding error codes from check engine light notices. All provided insight, but I am still confused on what plan of attack MY SITUATION calls for...

First off, I posted a note many months ago when the first CEL came on, inquiring about a dirty air filter and if that could be the culprit. The light went away, so I figured no harm (filter seemed as though it had some more miles left).

Fast forward to now, and the CEL has been flickering on-&-off for about the last month, (I don't drive it that much). So this weekend, I checked the code (and cleared). I am receiving error code P1125 (Scan tool read out 'Fuel Air Metering Control'), Loren's list reads this code as (Oxygen Sensing Adaptation Cylinders 4-6). This is the only error code listed from the scanner.

First Question: Cleaning the MAF Sensor seems fairly straightforward, is there any way that, if careful, cleaning can cause damage to an otherwise healthy sensor?

Second Question: Could it in fact be my first guess months ago of a dirty air filter that needs to be replaced? I will be replacing filter tomorrow regardless.

Third Question: Code is cleared, but will disconnecting the battery for 20 minutes "reset" the computer calibration for fuel/air mixture in case cleaning of the MAF and new air filter rectify the situation?

Thanks in Advance!!!!
-Tim

 

You can clean the MAF sensor with electrical cleaner with no harm to it (do a search at renntech for the correct fluid: from what I remember the cleaner is the non-fuming type). Second, the computer will reset itself after a few weeks when it notices that the MAF sensor is working correctly. I found this out by experience. I changed the MAF and learned only afterwards that it could be cleaned (out about $200 - yikes). Anyway, I was going to purchase an OBO tool so I could clear the CEL. Before I actually purchased the tool, I noticed that the light had reset itself. I will, however, be purchasing the OBO tool b/c it is a good idea to have one for diagnostic purposes. Good luck.

 

Thanks 'my996'. Yes, I too replaced the MAF about 18-months ago. That is why I was contemplating trying to clean it out this time.

Anyone else have an idea about the air filter being the culprit?

 

If you have an oiled filter like K&N or BMC that may be the problem. I was told after the fact that you must wash them in soapy water and air dry before installing. I have also cleaned my MAF with electrical cleaner with some success, just spray on the element and air dry. No harm can be done. Make sure the dealer sends you the correct one as they changed in 02. The best price I found was Brandywine. Will

 

I think washing an oiled filter in soapy water and air drying it would remove all the oil intended to trap the unwanted particulates, which is probably not a good idea.

I replaced my entire exhaust system (headers, cats, mufflers) and put in new O2 sensors and a K&N air filter and have never had the CEL come on. After all I had read here, I was waiting for it, but it never happened. There is probably a fine line that you have to tread with the amount of oil you put on one of those filters - too much and it trips the CEL, not enough and it lets too many particulates into the engine. I believe that someone here said to oil the filter as normal, and then let it sit on a newspaper for a while to let the excess oil wick away, but I can't remember who said it. I will be cleaning and re-oiling mine in the next 2-3 months, and I am crossing my fingers that I can get it right.

 

Absolutely! You only wash it in soapy water and air dry it when it's time to clean it because it's dirty, but then you re-oil it.

 

I had the same concern but those are the instructions I got from Todd at Evo. While there getting a dyno I again asked the mechanic and he confirmed that they do that to every K&N they install, even without the Supercharger. I have had no more MAF problems since I followed their advice. Will

 

getting a scanner is a good idea, i have one myself, but it is not necessary to clear the cel light. just undo the positive batter cable and leave off for a few minutes. reinstall and you are good to go. just be sure you have the radio code handy .

 

hey there,

what cats did you get? notice any change?

 

i have used "no residue forming" electrical contact cleaner. works like a charm.

 

Undo the NEGATIVE battery cable only. DO NOT undo the POSITIVE cable with the ground still connected as you greatly increase the chance of surge to the computer. On ALL electrical devices, the ground should always be disconnected before the hot side of a circuit.

It is also better to reset codes with the tool rather than disconnecting power to the DME. You eliminate having to wait for the computer to relearn engine parameters.

 

Replaced Filter and cleaned the MAF sensor with electronics parts cleaner that I bought at Fry's.

Here is a pic of the MAF, does it come 'apart' more than this? I sprayed it down real good on any and all contacts that I could find, including under, back & inside the hidden spots. Seemed too easy, is there more to it? Did I miss anything??



Oh yeah, I put her all back together and no check engine lights, etc. so far (only drove it about 5-miles). I will update after more time behind the wheel.

Thanks!
Tim

 

karlooz,

The cats were 100 cell cats from FVD, and the headers and mufflers were from Fabspeed. Since I installed everything at once (cats were rattling and needed replacing, and I figured while I was under the car...) I can't comment on the difference the cats made by themselves, but the car does seem to have more torque down low. That could be "audio-induced" torque, though, since I have never had the car on a dyno. All I know is that when I fire the car up the sound makes me grin from ear to ear. Just going by the visual comparison of the new cats versus the stock cats, I would find it hard to imagine that they don't flow any better than the stock ones.