Mxs backfiring /popping exhaust

No codes normally it will through a code for low vva pressure.

 

I have seen them with housings snapped and Iva solenoid hanging from the wires, no oil press codes logged just a code for the solenoid.

 

Yes me too but there is always a code because of the abnormal oil pressure when the ecm trys to activate the iva.

 

Broken injector springs, broken valve spring usually intake, or the IVA.
Just a thought!

 

If I remember right, seems like some of the mxs had an issue with cam sensor gap being to close, and needed to be shimmed out.

 

Thanks, no broken springs or anything. And the cat dealers around me can't find anything wrong. Waiting for a chance to get on a dyno. Maybe replicate the problem, I hope!

 

So what was the final diagnosis? I've had the exact same issue for a couple years now.

 

I have a 625 NXS doing this intermittently, ever figure out what it was?

 

I had a valve that was wearing into the head. It took 5 shops to figure it out. Ran over head at I27 repair in Amarillo. Took him like 2 seconds to see that one valve was 1/4" taller than all the others

 

Not the good news I was hoping to get but, at least now I know what to look for come spring. Thanks!