New Plugs, New Wires, cleaned the injectors (these looked fine) replaced the MAF, Replaced the IAC, removed and cleaned the EGR (had black exhaust on it), cleaned all the EGR ports and lines, replaced the Vacuum lines. Cleaned the Throttle body. When the car is idling fine, I Have sprayed every where with starting fluid to check for vacuum leaks, it seams OK there. The snorkel between the throttle body and Air box appears to be in good repair. (The Air filter box does have a broken ear on the non-latching side, but I have installed screws to hold that side tight.) After the car runs rough, I go home, open the hood to diagnose and it runs fine. It does seam more pronounced when cold. Also, I can sometimes hear a quiet popping noise from the exhaust at idle. Covered the exhaust output with hand and can feel exhaust. (It burns the throttle body cleaner out with white smoke after cleaning, so I don't think the cats are blocked) Mileage is still in the 28-30 range in the city. Once underway under normal driving conditions, there are no noticeable issues. IT did give a P0421 Warm Up Catalyst Efficiency Below Threshold (Bank 1) once this summer, I cleared the code and it has not returned. The 2 front O2 Sensors where replaced 12 months ago, due to check engine faults.
have the same problem?
Wednesday, November 20th, 2013 AT 12:18 PM