Thread: P0068 - Vacuum Leak at Boost Solenoid?

Hey guys,

I recently had my car tuned again for the winter upgrades. I'm now having trouble with a P0068 engine code and power limiting. It's making the car virtually undrivable on the hwy.

When I'm getting on the Hwy and try to give it more throttle to merge, the car throws P0068 and goes into limp mode. It's fairly consistent with trying to pass or climb any grade at hwy speeds (basically just before it down shifts this happens)

I've replaced the MAF and traced all the vacuum lines and those are all good. I did noticed that the little foam piece on the upper vacuum fitting on the boost bypass solenoid was gone though. I placed some tape over that fitting and now everything SEEMS ok. Could this be a vacuum leak causing the code? Is it "bad" to have it taped off versus having the foam there?

If it's not this, I think it's in the tune which would be highly inconvenient. Any input would be great. Thanks guys!

Gotcha. So that's not going to be causing a vac leak and it makes sense that the little foam that's supposed to be there is just an air filter.

Now when this happens, if I pull over, shut the car off, plug and replug in the MAF sensor, everything seems to work again. It obviously doesn't clear the code, but it takes the car out of limp mode. Any ideas?

Scan the car, graph the app and TPS sensors, make sure they agree at every position of the accelerator pedal position. The pcm detects engine load by the inputs of the maf and map sensors. So check the maf and map. Graph the maf, map, and TPS, the graphs should look like one another.. also over learned after market maf sensors are garbage.. so many times I've seen after market maf sensors garbage.. 3 in a row cars still ran bad and wouldn't idle, go-to the dealer and get a oem maf car was fixed. Same with my daughters Camry. So if you bought a non acdelco maf take it back. If you need more help let me know. If your in Wisconsin I know I could scan your car, take it for a ride and pinpoint your problem within minutes, but I will help you the best I can thru the forum here. Your tuner could have messed up the maf, TPS, or map tables too..