i just ran a OBD-I diagnostic code reader on my 95 gt again and got the KOEO codes 181 and 189. i know that these codes mean its running too rich, but have no idea where to start in fixing the prob. thanks
Actually, the codes mean that you're running lean (the nomenclature you read might have said that they were at the 'rich adaptive limit', which means that the puter richened things up as much as it could but it's not enough).
Things that can lead to this are a dirty/bad MAF, vacuum leaks, bad O2's and so on.
Good luck.
Also, perhaps a mod can move this to Tech. It's not really tuning-related and will get more replies/views in Tech.
(Maybe a mod. can also move my recent thread about MAFTuner wiring - it's not really tuning-related and no one is viewing it in here [though this was my target audience - those who use those kinds of instruments] ).
oh yea, i originally misread the codes i received. thats odd though, cuz during the summer i ran it and got two codes meaning it was running rich. since then i have: cleaned the MAF, throttle body, intake manifold, installed a CAI (sort of), and cleaned the distributor car and rotor. now im stumped.
There are myriad reasons it could have switched from runnin rich to lean. The tune-up work you did could do it. The CAI installation (is it a true CAI or is there an open air filter under the hood?) could cause a MAF signal issue, which can certainly cause a lean condition. Oil from a new CAI filter can cause a the MAS wires to get contaminated, which can equate to a lean condition.
A dirty fuel filter, vac leak or failing O2's can also do it (amongst other things).
It often takes some digging around or seeing PID's/Datalogging to see what's going on.
Now that codes are known, it can be helpful sometimes to clear the codes and see how long it takes to generate fresh ones, and what they are. I'd especially do this if your codes were KOEO and you didnt clear codes after the tune-up work.
Good luck.
its a homemade cai. before the MAF i put a L-bend PVC tube into the fenderwell with an ioled k and n filter. perhaps the oil from the filter is messing with the maf. ive tried clearing the codes multiple times as per the manual for the code reader, but am never really sure that it actually clears them.
For some folks, clocking the MAF seems to help a lean issue. It can be worth trying.
As for clearing the codes, I like to disconnect the negative battery terminal, create a draw (steppin on the brake pedal for 10 seconds works for me) to clear the capactors in the computer, and then reconnect the battery. This clears the codes and gives you a fresh slate for the computer to relearn (with respect to the adaptive control).
I'd give that MAS a quick cleaning too - just incase. It takes but a couple minutes to do (removing the two security Torx fasteners as a means to access the sensor).