Black01Bird

More code troubles, it seems for every one I fix two more pop up, I sea foamed my gas a few weeks ago (not sure if this has anything to do with it) but a few days later I got codes po171 and po174 which is bank 1 being lean???

Well I set my scan gauge 2 up to read afr and I'm not sure if its accurate or not but its reading 14.6 in closed loop... So wtf is wrong now and causing it to randomly throw these codes? I've erased them twice and the check engine light comes back on right away, also have a code po420 for awhile if that means anything.

Thanks tech!

wssix99

iTrader: (5)

This has all the hallmarks of a dirty MAF.

Black01Bird

Alright just went out and cleaned it with electronics cleaner, and when i got the car it had Thunder Racing MAF ends, and i noticed today when i took it off that there was no screen... the lower right hand wire was also BLACK. So i guess ill drive it around like normal and see if the code comes back...

Black01Bird

Just went back out to check for vacuum leaks, as soon as i opened the hood i looked at the pcv line by the TB, and what do you know.. a pretty big hole in it -.-... hopefully fixing that cures these codes now!

Black01Bird

Code hasn't come back, now I jump in to head to work after at least 500 miles driven and the code came back but now just the po171, wtf?!

wssix99

iTrader: (5)

The common possibilities are all right here: http://www.obd-codes.com/p0171

If your O2 sensors have a lot of miles on them, I'd change them out next. The codes could all be due to a number of things working against you. I'd bet that cleaning the MAF earlier and fixing the vacuum leak still all helped.

Black01Bird

I'm about to go out now and start checking some things, it's just weird because (if its accurate) my scan gauge 2 is reading 14.6 afr cruising, and 11.6 at wot which are both where they should be, but I knew the code popped again because my mpg randomly went up about 2mpg, so I checked and sure enough had the code.

wssix99

iTrader: (5)

AFR doesn't mean much in this instance because the sensors in the car are either not reading the correct amount of air coming in the engine or are lying about the amount of Oxygen going out the tail pipe.

Your AFR may be correct, but if the computer is reading a bad value for air flow, the delivered proper AFR will equate to the wrong amount of fuel to the engine.