Hey guys, does it sound reasonable or possible that a car would throw a SDL/CEL when left running in a garage for a while? Whilst the garage door was open, the car was reversed in so would have been sucking in its exhaust fumes… you could barely breathe in there… came on after about 15 mins of idling. Due to O2 depletion in the garage perhaps? took the car out today for a spirited drive, no lights but I’m still concerned. I hate dash lights. 355 2.7. Cat ECUs and 02 sensors replaced 5 years ago, cats are original from 1994….
Hypothetical, maybe(????). If the air was so depleted of oxygen to start with the exhaust gases would be even more depleted. The longer it runs the worse it gets. The O2 sensor would interpret this lack of O2 in the exhaust as a rich condition and reduce fuel delivery towards the lean side. If it were so bad it might push the O2 sensor beyond the max correction limit, resulting is a CEL. However, the engine wouldn't really be lean, just trying to reach the correct A/F for the amount of O2 coming in. But I can't see how this would generate and SDL since, introducing exhaust gas in the intake and lowering fuel delivery would (should) result in lower exhaust temperature, similar to the function of the EGR system on newer cars.
You can read the codes on a 2.7 via the dash light blinking. You have to read each bank independently, but not difficult to do. If you haven't reset the battery you can probably still get the stored code.
There are, as bobzdar has said. The 2.7 makes it easy to get the codes. Don't reset the car until you at least attempt it. This will help narrow it down.
You need the button for the ECU. He doesn't have it as it's only on US cars. If the harness has the pig tale where the button connects it would be easy to make one as the parts are US NLA. You could use a remote started button for the switch. Then just a matter of getting the right the connector and selecting the correct wires. He did do a rest but I'm not sure if the codes get erased on a 2.7 car. The CEL will go out but the codes may remain. That was the experience I had with my 2.7 car when I got it. No CEL but codes said a Temp sensor was bad.
Thanks Guys, point of the thread wasn't to ask how to pull codes, it was a question as to whether excessive fumes/lack of 02 in a garage would lead to a CEL. In theory it would due to the O2 sensor going very low range, but I'm just curious as to whether others have seen this.
