Check engine codes point to EGR valve and throttle position sensor. Have replaced EGR valve, EGR solenoid, and throttle position sensor. No other changes.
Before these new parts, I could drive 5 miles to 10 miles before the light came on -- other times I could drive all day and no check engine light. Now, the check engine light comes on almost immediately and stays on.
Replaced the catalytic converter last year, has new plugs, filters, plug wires, air filter and running temp is normal. What am I missing / what else should I check? TIA