I have a customer with an 01' LB7 Dmax and we cannot figure out what makes it go into limp mode. We just changed out the MAP sensor today and it still keeps popping a P-0234 overboost code. This usually happens at cruising speed, 70 - 90 mph and is only boosting 7-10 PSI. Any help would be appreciated.

Just FYI, the mods are EFI LIve DSP5, PPE lift pump, Volant Intake & 4" turbo back exhaust.

My 01 was going into limp mode when ny injector went bad, dealer "thought" it was the tranny. Long story short 3700.00 later new tranny still limped. another 1500.00 new injector, no limp. Good Luck

My 01 was going into limp mode when ny injector went bad, dealer "thought" it was the tranny. Long story short 3700.00 later new tranny still limped. another 1500.00 new injector, no limp. Good Luck

He just had all 8 replaced 4 or 5 months ago, no fuel smell in the oil, and it's not overfull. No white smoke, new Fuel Pressure Regulator last week. Any other thoughts? CP3 or FPRV?

I dont know if this helps but my truck did the same thing with my Quad programmer. I used to get the code all the time. I switched to PPE and have never gotten it. Could it be something with the EFI tunes?

It could be, he got the tunes from someone else, but it also did it with Hypertech he ran before he put the EFI on.

pm replied to

PM received, thanks.

Long shot here, fuel filter?

Thanks Josh, just put a new filter on last week.

anything new?

Put a PPE code eliminator in at his request and it just threw the overboost code after 200 miles, which is about 190 more miles than he would get with it out. He just called to tell me 5 minutes ago. Looked at the charge pipes and no leakes anywhere...

If we have time make him buy a license

He hasn't called since he turned down the PPE OBCE.

Well since I had a similar issue, and you already tried the fuel filter idea...what do you think about his truck possibly having injector issues. I know this was my next avenue when changing the fuel filter did not work...and sure enough it was injectors.

Well since I had a similar issue, and you already tried the fuel filter idea...what do you think about his truck possibly having injector issues. I know this was my next avenue when changing the fuel filter did not work...and sure enough it was injectors.

Could be but the injectors were done less than 10K ago, all 8 of them.

Could be but the injectors were done less than 10K ago, all 8 of them.


They could still be bad again....I know I am reaching pretty far but hey....:o:

mass air flow sensor fixed my 01 when i had that problem

I had the same problem and a Mass Air Flow sensor fixed mine also.

I had a truck where the mires at the boost sensor were shorted out, if I moved the wires at the plug I could watch the boost change on the tech2. I got a new plug and it fixed the problem.

crank position sensor or the thing the sensor reads works loose and falls off. Have to take the pan off and put back on. Dealer had to call gm tech. I do not know if there is bulliten or not. Exact same simptom

:cool:parameters not set right for boost with efi had same prob

:cool:parameters not set right for boost with efi had same prob


x2!!!!

first day i had efi live i threw overboost code