R sensitive to oil levels?

[langer]

This may be complete coincidence. Had a CEL for quite a while, might have been since last oil change. Intermittent initially but has stayed on for last several thousand miles. Catalytic inefficiency code. Changed my oil/filter on Sunday. Noticed I was maybe a little under a quart overfilled, my mistake. I always pour my used oil back into oil 5L oil bottle, and this time I overflowed the container with some left in topside oil extractor. Oops. But, driven a couple hundred miles since and CEL is nowhere to be found. I have an AWE downpipe with hjs cat. Even bought j spacer and new o2 sensor to install before last oil change. Could just a quart or little under a quart overfill cause some fouling of cat/o2 sensor?

 

[jay745]

Doubt that's it. These engines aren't sensitive to minor over filling

 

[scrllock]

This may be complete coincidence. Had a CEL for quite a while, might have been since last oil change. Intermittent initially but has stayed on for last several thousand miles. Catalytic inefficiency code. Changed my oil/filter on Sunday. Noticed I was maybe a little under a quart overfilled, my mistake. I always pour my used oil back into oil 5L oil bottle, and this time I overflowed the container with some left in topside oil extractor. Oops. But, driven a couple hundred miles since and CEL is nowhere to be found. I have an AWE downpipe with hjs cat. Even bought j spacer and new o2 sensor to install before last oil change. Could just a quart or little under a quart overfill cause some fouling of cat/o2 sensor?

aftermarket downpipes will almost always trigger a P0420 eventually. I have a pricey GESI EPA cat and still get a code every month or two. stage 2 tune should disable the CEL unless you're stuck with cobb.

 

[kevinkar]

Most engines are not sensitive to over filling or under filling for that matter as long as there's a reasonable amount of lubrication circulating and enough for the system to circulate efficiently without cavitation somewhere. Fill your engine to the low mark and then check how much more oil is needed to reach the high mark. Probably close to a quart. That's the tolerance for the "proper range". Less than that you really ought to add oil but going over that won't kill the engine. Certainly not raise any CELs.

 

[langer]

Damnit. Ha. I thought I got lucky with CEL. I figured that slight overfill wasn’t enough to cause any frothing. Just waiting for it to trigger again. I don’t think newer stage 2 tunes will disable the downstream o2 sensor any longer, but I may be wrong. I just have a jb4 on there with intercooler and downpipe.