Mass Air? Oxygen Sensors? What Could It Be?
 

heres the problem, my 91 lx isnt running properly, smells wayy too rich, not as much power as i feel it should have, and when im WOT for like 5 seconds(hard on in 2nd through end of 3rd) the check engine light will FLASH on then when i let off, it goes away.
ive pulled codes and i did have a KOEO code 56 (maf above max voltage) but found nothing o2 related. could the maf being above max voltage cause these issues? i was told its "probably" my o2's but i dont know for sure and dont want to spend a bunch of coin and find out that wasnt the problem.

any way to do tests(that i can perform at home) to figure out what the problem actually is? any info greatly appreciated!

Re: Mass Air? Oxygen Sensors? What Could It Be?
 

It's probably your mass air....Try to clean the element inside with some carb/fuel inj. cleaner, but just be careful not to damage it. If caleaning it dosen't fix the problem, you can pick up a used one on e-bay.
Good luck.

Re: Mass Air? Oxygen Sensors? What Could It Be?
 

any auto parts store will scan your car with a KOER test. Bad 02's could indicate a full lean, and the PCM compensates by referencing the get-home table and forces the injectors to run full rich.
good luck

Re: Mass Air? Oxygen Sensors? What Could It Be?
 

Second Hozer 88GTConv, but you can run the KOER self-test yourself, follow the procedure right here @MustangWorks and LUK what KOER codes you get. GL

Re: Mass Air? Oxygen Sensors? What Could It Be?
 

I have had problems with the mixture that were solved by replacing the O2s, but never saw an engine code.
Not saying it will work for you, but sometimes bad O2s don't throw codes.

Cleaning the maf as described above is a very good place to start. I would use Brake Cleaner though, as it will not leave ANY residue behind, unlike most solvents.

jason

Re: Mass Air? Oxygen Sensors? What Could It Be?
 

Another thing to worry about is, if both O2s are bad and are throwing codes, they may not be the problem, usually if they both throw codes, it means it's a bad MAF.