Hi all,

I did the crossover/thermostat job, and besides overheating when it failed, the vehicle was running fine. Once reassembled, it now is throwing codes for each cylinder. I cleaned out the plugs, made sure everything was plugged in correctly....in fact, I removed and reinstalled everything right down to the intake manifold.

Symptoms are that it runs rough, accelerator will make the rpms rev really high once and then it dies off. Cannot maintain idle, stops with any fuel given.

Any suggestions?

Thanks in advance.

 

Misfire codes? Post them.

 

I don't have the fanciest code reader, but:

P0300
P0301
P0302
P0303
P0304
P0137
and also the above 6 codes repeated with a "pd" following each one.

 

What year R56? N12, N14, N16, or N18?

How badly did the engine overheat?

For downstream O2 sensor code P0137, check whether the connector may be contaminated with coolant or whether you potentially swapped the O2 sensor connector with another sensor connector.

 

If you had the intake manifold off, I’d be tempted to think you have an intake leak or something didn’t get reinstalled correctly

 

It's a 2008 n12 non-turbo. I pulled off and headed towed when it started to overheat, so not too badly.

My thoughts yesterday as well were that maybe I swapped a couple of sensors, but I'm not sure which sensors would actually be able to be interchangeable?

I'll check the o2 sensor connector, thanks

 

I would double check the vacuum lines and hoses under and around the intake, then check the plugs around the thermostat

 

Good question. I can't think of a nearby 4-pin connector that can be swapped with the downstream O2 sensor connector. Just for verification, check whether the wire colors match the wire diagram (orange, white, yellow, black).