Reading on the board I think my APPS went out but have never seen these two codes together in any of the post. What I have and what is happening:

- 1998.5 24v 5 Speed 2500 Quad Cab, have a Smarty installed but on stock settings, no gauges yet, no mods to truck, 140k miles on stock VP pump as far as I can tell

- Getting dead pedal for 4-5 seconds with a CEL, always seems to come back on right after

First couple of times it did this I got the P0121 code which points towards the APPS. It's been getting worse so I just checked the codes again and it threw a P0234, overboost for the turbo. Do you guys think it is just my APPS or could the map be going out too? Just want to confirm before I buy the TIMBO replacement APPS. Throttle seems to be smooth other than when the CEL comes on. Thanks for any help.

 

Have you done the APPS adjustment? The over boost code seems to happen to most any truck from what I've seen.

 

The APPS adjustment on the stock one or the aftermarket one? I still have the stock APPS. Thought you only adjusted the aftermarket one, am I wrong? Let me go through the FAQ's again. I have not tried to adjust my stock one.

 

Yes stock is adjustable. It fixed my last truck for almost a year before needing replacement. You'll have to do a search for it here. Good luck.