Dirty tail pipes, your car is running rich, which is a lot better than lien. I don't think any one on here has had any luck with other CPS's other than Bosch. It could be that, it could be the RCM with the solder joints. I have had the one car run rough, but didn't die, and it was the CPS. It was hard to start as well. That is where I would start. It isn't fuel, or it would continue to cause a problem, especially since the engine code went away.