Just picked up an old wagon wasn't running the best now seems to be worse. changed plugs, wires, cap & rotor, new air filter, changed the oil, and cleaned the maf. (with MAF cleaner) It idles and revs just fine, though under load it stumbles and sputters. The check engine light comes on after a while but I don't know where to plug in and see what it's saying. Any help would be fantastic.

forgot to mention when I got the car it was without an air filter. Now, having replaced it, it runs worse. When I take it out seems to run a bit better.

You should change the fuel filter before you do anything else. And if that doesn't cure it run a check on the fuel pressure.

 

If you plug in the two green connectors under the dash the ECU will flash the codes to you in long/short flashes.

 

GD

Thanks!

 

btw, how many PSI should this car have?

21 if the regulator is working properly. 50 from the pump if you pinch off the return line.

 

GD