Hesitation, engine light

[fossten]

I just got my '93 MKVIII tuned up, but a recurring prob. will not go away. The car hesitates and vibrates/bucks when accelerating in a high gear while in traffic. The check engine light comes on, too. I have taken this to a shop, but the car doesn't do this all the time, so it's hard to catch it in the act. In any event, I need to take it back but I don't know what to tell them to look for. I don't know what the code would be, either. Anybody else have this happen?

 

[chump2825]

its your 02 sensor

 

[fossten]

its your 02 sensor

I was afraid of that...

 

[98LSC32V]

I would check the codes it might not be oxygen sensors. Who knows what it is what type of tune up did you do? Could be an ignition problem or maybe a fuel problem.

 

[fossten]

I would check the codes it might not be oxygen sensors. Who knows what it is what type of tune up did you do? Could be an ignition problem or maybe a fuel problem.

I had a tuneup, oil change, all filters. Then I had the injectors flushed. Decarbonized combustion chamber and cleaned fuel rails, screens, intake valves, and manifold. Replaced throttle body assy (bad idle), idle control valve & gaskets, cleaned throttle plate & idle air bypass. Serviced trans., flushed cooling system and brake system.

The codes I had were:

176 - EGR not switching, lean exhaust bank 2
177 - EGO not switching, rich exhaust bank 2
524 - Low speed fuel pump circuit open
543 - Fuel pump circuit open, battery to ECA
634 - Manual lever position sensor out of range
412 - Cannot raise RPM - extended idle
411 - RPM out of spec - normal curb idle

I called my mechanic and he doesn't think it's the O2 sensor b/c it didn't show up in the codes. I told him the car doesn't do it all the time but he said it is all in what the codes say.

 

[fossten]

Bump

 

[Jibit]

have you checked your fuel pressure?

 

[fossten]

have you checked your fuel pressure?

I have no idea how to do that, I'm not a mechanic. I'm trying to learn.