So, I recently changed the oil in the car. Nothing more. nothing less. No CEL prior to oil change. Post oil change, CEL immediately on, with a P0171 (Bank 1 Lean) code from my bluetooth OBDII reader. I cleared the code and immediately the display read 'high engine temp see manual' with temp gauge pegged in the red. Shut car off and fan ran for several minutes to cool block down.

I changed the air box filter after all this mess. I also noticed a cracked plastic park near the airbox (I have no idea what part it is, see photos below). I'm hoping it's just that and nothing serious.

Any help would be appreciated.

Here is photo of broken part.


Broken part close-up.

 

That would be the brake vacuum pump switch. It has nothing to do with the engine overheating

 

Ok, well that clarifies that. What would cause the overheating otherwise from a mere oil change?

 

It doesn't seem related to the oil change.. I would inspect the temp sensor wiring on the thermostat housing. At that age the thermostat is also known to stick but usually it stays open so it shouldn't overheat. It looks more like some electrical gremlin. From a cold engine, does the temp gauge climb directly to the red zone in a couple of minutes? How many miles on the car?

 

the temp sensor appears to be in decent condition. Started the car today and no CEL nor high temp on text box. After about 10 minutes, CEL appeared with same code P0171 (lean Bank 1). Car doesn't appear to be overheating; temp gauge is dead center. Any ideas on the P0171 code?

 

Found this. 'Maybe' fresh oil and filter had something to do with it.

P0171 System Too Lean??

 

An oil change will not cause a lean code. A vacuum leak, like from the damaged brake vacuum switch, will.

 

Looks like a good read. Thanks. I'll check it out.