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I bet it could throw a running lean, MAF or O2 code… but it may not be enough to throw any codes. It’ll make the engine run poorly as it’s a vacuum leak. I’d at least plug it till you can actually fix it. Plugging it is a perfectly fine fix if you don’t care about how the AC functions.Still haven't had a chance to look at this yet. We've had crappy weather here and I haven't wanted to mess with it. Will this line not being attached give me a CEL?
That’s the heater core bypass valve. The top part with 4 hoses is coolant in/out and heater core in out. The bottom part is a vacuum powered valve that switches between having coolant run thru the core and bypass the core. I don’t have that in my truck so can’t run out to check. Id imagine that there’s be a vac line to that valve AND a vac line running into the cab to control the heated air blend door. This is only important to diagnose proper HVAC operation.I connected the vacuum line to the area circled in the pic. I'm still getting a P0171 code. I have replaced the IAC valve, the the throttle position sensor as well as cleaned the MAF. Any ideas??View attachment 72339
It’s on the other side of what you circled red looks like two prongsI connected the vacuum line to the area circled in the pic. I'm still getting a P0171 code. I have replaced the IAC valve, the the throttle position sensor as well as cleaned the MAF. Any ideas??View attachment 72339