Chris texted me looking for a downpipe with cat. must be plugged; happens a lot. particularly with a tune haha

 

No tune, bone stock, looking into all avenues ATM

 

I had a very similar problem ten years ago with my Saturn LS2 (3L V6 4 speed auto). The check engine light would come on intermittently, and the transmission would start very hard shifting. If I stopped and turned the engine off, and back on again, it would clear itself.

The dealer couldn't track down the problem, claiming they could only diagnose it if the check engine light came on. I even left the car with them and a technician drove it home for a couple of days trying to experience the problem first hand.

After several months of this, it deteriorated to the point where the light would come on regularly and the dealership finally dropped the trans and declared it junk. They installed a replacement under my extended warranty.

As I recall, it was some sort of actuator valve/assembly that was the problem, but my trans was too far gone.

 

Is there any way I can check the evap system?
I've changed the air filter, changed the injectors, cleaned the throttle body, new plugs, a diff maf (not brand new), cleaned both mafs, o2 readings r normal afaik.

 

Brought the car to gm, was told that the ECM needed reprogramming so fingers crossed Shea good to go

 

 

? wrong injectors for calibration in a stock car and has worked for years and now doesnt? weird. x files stuff