Stumble on Acceleration and Bad Mileage
So, I've been fighting the gremlin in my 2.4 with hiccuping on acceleration and 22 MPG highway. I have the car in my garage now to do a timing chain, so I'm trying to diagnose these issues, but would like to know the things to check for. I've changed o2 sensors due to a P1174 code. That went away. Throttle body got cleaned, tranny fluid and filter changed, new spark plugs, fresh oil change (every 5,000 miles). No CEL's. Anything else I can check for? Is there a way to test the throttle body module or other sensors with a multimeter? I'm at a loss. I'm trying to troubleshoot possibilities before biting the bullet and taking it in.
2006 Cobalt SS/NA