I have a coolant leak on the rear pass side of the engine. I installed a 180 thermostat this morning to hopefully Slow/stop the leak. I ordered a head gasket kit from Rovahfarm and other o-rings and intake gaskets. I hope its a valley gasket and not the heads. If its the heads I am thinking of doing a oil pump and possibly a cam. Hopefully doing the intake gaskets and injector o-rings will solve my p1171 code.

 

My coolant leak on right rear of engine turned out to be only valley gasket. I pretty much determined this before disassembly, by crawling on up there with a flash light. Leak was too high to be head gaskets.
If memory serves, P1171 is a too lean code. Have you checked oxygen sensor and IAC performance? But you are likely on right track with intake gaskets and injector o-rings. Good time to clean injectors.
Good Luck!

 

Same thing I had too. valley pan gasket. Like Nick said. If you can climb up and look down where the coil packs are in the back of the engine with a light, you'll probably see the top of the transmission wet.

 

1171 is not causing your 1171, start looking for a vacuum or exhaust leak.