check engine light on running lean

nitto389703 · Oct 19, 2012

so after a storm passed by vegas my car got somewhat flooded carpet got wet. started the car and went to the back to see water coming out of the exhaust and check engine light on. so went to autozone and i have bank 1 and 2 running lean , bad 02 sensor or low fuel pressure. my car has long cranks times and low rpm start up first 2 seconds. so i used the fuel pressure test and when the key is in on 0psi but cycle the key 2 times about 10 psi then drops to 0 in about 2 seconds. cycle the key 5 time fuel pressure goes to 40 the falls fast to 0. at idle it at 39-40 psi, engine rev 45+ psi .
i gave all the info i could remember if some one could point to me a right direction as to whats wrong with my mustang. im thinking maybe a bad fuel injector staying open or fuel pump both expensive..

note fuel filer replace yesterday but no improvements.

BigBore96 · Oct 19, 2012

Clear the codes completly again and rerun it and pull the codes just to make sure what comes back. I would let it the car idle for a good while to clear out any moisture that could still be in it. Assuming it will idle of course

Check the voltage to the pump harness when cycling the key, have a friend help as its next to impossible without.
It's possible the 02s were messed up. It doesnt hurt to replace them anyway.

As far as fuel injectors/pump.

Theyre not hard to replace and are relatively cheap. Espcecially for stock size injectors and fuel pumps. Even a 255 fuel pump can be had for like 70 shipped.

nitto389703 · Oct 19, 2012

she idles fine runs great i took out one 02 sensor, apparently i have 4

it seem good and dry on the codes it wont tell me which 02 sensor to replace. can they be tested with a Multimeter?

BigBore96 · Oct 19, 2012

The rear 02s are basically telling the car if the cats are working.
The fronts are the ones I'd worry about. I have no idea if they can be tested.

What codes did it throw?

nitto389703 · Oct 20, 2012

code p0171 po174

nitto389703 · Oct 22, 2012

check engine light gone been off for two days hopefully it doesn't come back. check all my vacuum line to find out that the PVC hose had a hole in it. AutoZone gave me one for free ;-) reset my computer an im very happy.a small 1$ piece can cause alot of problems.