Greetings.. my car sounds rough during idle. drives fine, no problems. my CEL stays on, Autozone pulled 2 codes P0102 and P0170. I looked up codes on eBahn/Bentley site, however, the P0170 is not listed as a possible code for a 2001 2.8L A6? I had to look back to 1997 to find the p0170 (fuel trim bank 1) is this typical for a code that is not listed as a possiblity for a make/year to appear?
Anyhow, for the P0102, I have already removed the MAF sensor and washed it in 91% isopropyl. When I disco'd MAF, car sounded almost the same, which led me to believe bad MAF. However, my hubby has same make/ model and we removed his MAF and placed into mine...no difference in idle. So now I am not sure the problem is the MAF. Vacuum hoses look in good shape, could a simple clogged fuel injector trip the 2 codes? If so, is it safe and/or effective to use fuel injector cleaner on these cars?
Trying to save an expensive trip to the dealer..any info/suggestions greatly appreciated.
Best Regards, Mrs. A.

 

yeah. i dont see the p0170 as a code as well, but it does have to do with fuel trim and control there of.. so id eliminate the p0102 first.. that problem could and more than likely is causing the fuel control problem and the p0170... you may have a dirty mass air flow or a leaky hose past the mass air flow causing it not to read properly the amount of air passing through the intake being mixed with the amount of fuel that the maf is reading.. which is wrong... wow that was a run on sentence.. but for sure solve the maf code first.. make sure your getting voltage to the sensor, then make sure you get a ground.. then check your signal return and compare with some good known numbers.. then if they are all right and your fuel trims are way positive or negative then you have either an air restriction(causing a negative fuel trim due to rich condition) or a vacuum leak(causing a positive fuel trim due to unmetered air in the intake)

 

Replace the MAF.

www.ecstuning.com

 

Greeting..
Bigern and Crazyhawk thanks for responding. I am such a novice in this arena...but I just can't afford $$ to bring car in to service so I am extremely grateful for your info, patience and time with my questions.
I went to autozone to clear the codes after cleaning MAF. How much driving will it take for the ECM to cycle through to have the CEL reappear if this didn't solve issue? Or will the code(s) be readable if Autozone plugs in, even if they don't cause a CEL yet?
It's hard for me to hear any leaking sounds over the rough idle engine sound. Is there an easy way to look for leaks without having to pull off vacuum hoses and smoke test? Sorry,if I sound silly with any of my questions.... but can I put a bit of soapy water on the hoses and look for any bubbling?
Checking voltages and return is way out of my league right now..but I may start learning real quick though how to use a voltmeter if I am to keep financially afloat with this vehicle. LOL,,(spent $1600 for timing belt/water pump replacement maintenance with my last tax return)
If cleaning or checking for leaks doesn't work, I will replace MAF temporarily with one from another exactly same vehicle to see definitively whether the MAF is the issue before I fork over $$ for a new one.
Happy New Year to All :-), Mrs A.

 

you can use carb cleaner and it will cause the revs to increase temporarily when you find the vacuum leak.. the water and soap will only work when looking for a boost leak.. (and there is pressure on the intake from throttle being revved up or a tester).. and questions arent silly, just hard to diagnose just from typing descriptions.. us techs like to see the problems up close to confirm..;-)