ok i have just replaced the opti, and now i keep fouling plugs on the drivers side only, they are definitley gas fouled, last time i replaced them they lasted about 150 to 200 miles of driving, i replaced the plugs and the drivers side 02, they fouled BAD! the first time i drove it!!! my fuel psi is reading about 50-51 psi, i think it's just running rich as hell and might need a re-tune now. my tuner insisted it was the o2 and it would be fine, but they fouled in under 50 miles now.

any other ideas????

 

When do you see 50-51psi fuel pressure?

If you are comparing that to the normal "cruise" fuel pressure (vacuum compensated) of 36-38psi, then your injectors are flowing about 17% extra fuel. The long term fuel corrections can only pull out 15%, but then the short terms tend to make up for the difference. But excessive fuel pressure would cause both sides to run rich.

Assuming you have the correct plug appearance on the passenger side, you have to find a factor that would only affect the drivers side. Typical places to look are exhaust leaks before the O2 sensors, misfires, a faulty O2 sensor or messed up O2 sensor wiring. A plugged injector could also cause one cylinder to run lean, and force the PCM to dump extra fuel into the entire bank of the engine, based on O2 sensor feedback.

Is it possible that when you replaced the Opti, you messed up a couple of the plug wires for the drivers side.... not simply crossing them, but damaging the ends if they were corroded, not getting the end fully seated in the Opti wire tower, etc?

 

i see 50-51 psi at idle and it stays there, occasionally it will drop to 48 when im driving but just goes right back up, right now the only thing i have not checked that you suggested was injectors, how do you check to see if one is plugged??

 

Injectors can be checked by pulling up the fuel rails with the injectors still attached to the fuel rails. First turn the pump on with the fuel pump prime connector and look for injectors that are dripping when they are off. Then remove voltage from the prime connector. Then have someone crank the engine over and observe the spray pattern from each injector.

If, and I doubt you are actually reading 50 pounds, it is correctly at 50. There must be a restriction in the return line. As stated above, if the pressure were the reason for fouling, it would effect both sides.

Have you checked for dead cylinders????? I would start there.

 

thanks, the 50 psi is just what the autometer fuel pressue gauge is reading, so i dunno. as far as a dead cylinder goes, wouldn't the car be running like absolute crap all the time??? it runs great when i replace the fouled plugs they just dont last long.