2003-2011 [Subscribe to Daily Digest] |
I have leaned on the expertise of my fellow SAAB enthusiasts in the past, Thank you, and come to you again to find guidance. My 2.0L engine with 183K well cared for miles has me at the limit of my knowledge. Here's what's happening.
CEL CODE light appeared, P0420, cat-con efficiency, OK, no problem, expected with these miles. A depleted Catalytic Converter?
MPG's had dropped from 27-29 down to 24-26, mixed urban and rural driving.
Firstly replaced upstream and downstream O2 sensors, OEM Bosch units.
Result; MPG's returned to typical range initially, but CEL CODE remained or returned after a short time after erasing with my code reader, but happy to have MPG's back.
After around 500 miles MPG's were returning to 24-26 range, bummer.
Next try, replaced the CAT-CON with a Magnaflow direct fit replacement, went pretty smooth but spent all day Saturday crawling over and under the chassis. OK, if that's what it takes.
Waited for CEL to disappear on it's own, didn't after 100 miles, so I erased it with my code reader after it did not exit the system on its own.
This was aprox 300 miles ago, and the code has not reappeared, but MPG's are still the untypical and lousy 24-25 range, mixed driving.
Today, pulled spark plugs, NGK Iridium I believe, which showed evidence of a rich fuel mixture, black carbon build uniformly among all four plugs, which is recent since this issue occurred. I've inspected and replaced plugs as good maintenance is important, so I know they were operating clean in the recent past, before this CEL came on the scene. Also, engine temp is in the center of the dash gauge, knowing a rich mixture is part of the cold engine temp.
I am at the limit of my tech knowledge for diagnosing sensors and such, so any guidance or help would be very much appreciated. Hope I haven't thrown away $500 and two Saturdays. Thank you SAABNUTS! Kevin
posted by 207.118.17...
No Site Registration is Required to Post - Site Membership is optional (Member Features List), but helps to keep the site online
for all Saabers. If the site helps you, please consider helping the site by becoming a member.