A couple of weeks ago, I was tool'n around town and realized my Quad XZT was on high performance setting. I switched back to the low setting which I run all of the time. However, shortly after switching down, the engine light came on. The code was P0237. Since then, I have hardly driven the truck. Today, I disconnected the Quad XZT and drove the truck to run some errands. After a few starts, the engine light went off, and when I checked codes, only the P1698(I think?) was displayed. Here's my take on this. The truck was never over 40mph when the XZT was switched to the hi setting. It was dumping fuel with very little boost, and the MAP sensor thought the boost was failing- thus the P0237. Make sense?Thanks guys,Eric

I think if that was the case, everybody would have this problem.

More than likely there is a problem with the Quadzilla XZT boost fooler being the code is present with the XZT hooked up but the light goes out after unhooking it. P1698 is a CCD network error.

I figure the hi-perf tune has an error. If I can find the tunes online somewhere, with descriptions, I'll change. I'm gonna reconnect the XZT and run it on econo mode and see what happens.