I compared the inside of my stock y-pipe to the inside of my Budget y-pipe and the inside of my stock y-pipe is clean/white whereas the inside of my Budget y-pipe is BLACK!

Is this a sign of me running rich? If so, I could be missing out on a bit of power there??

Lastly, if I AM running rich, how do I fix it? Since we cannot tune a/f, I would think that the O2 sensors are the culprit here. Since the inside of the Budget y-pipe is black, could it be that it also clogged up my O2 sensors? If I replace them, would that take the problem away?

Thanks for any help.

 

black is just soot buildup (carbon buildup). if you see black smoke coming from the muffler then you might have an issue. are you getting horrible gas mileage or a feeling of no top end power? best way to keep a/f stoich would be to check o2 sensors and maf. another possibly is a malfunctiong injector. these will typically throw a ses light though. also check the air filter to make sure its not clogged up.

 

But what I find odd is that there was no black buildup in my stock y-pipe which had been on for 8 years! I've only had the Budget y-pipe for 2 years and that is all black inside.

No SES codes or stored codes.

As for what's coming out of my muffler, there's blue smoke since I burn oil (even though my comrpession is very good)... but there is black around my muffler tip too...

Gas mileage is very good. Top end power is always good with MEVI/JWT ECU But I wonder if there is MORE that is untapped!

 

Remember the stock Y pipe has 2 more cats that are there to filter out your exhuast.

 

Yeah the pre-cats... they do a lot in reducing emissions too. But I have looked at other Maximas, even the same year as mine, with the same mods and they do not have as much black that I do inside their Budget y-pipes and out the exhaust tip... that is what got me wondering.

 

Dude, you said it yourself. Your burning oil... Oil will turn the inside of exhaust components BLACK.

 

Yeah you are probably right... and that's what I thought too until I swapped my stock y-pipe back on... my O2 sensor tips are now white again!

 

Well that's because your pre-cats are hot enough to burn up the oil before it makes it to your 02 sensor's.