I'm getting my longtubes on sometime late Feb/early March. I have noticed that there is a thin dust covering of soot on the inside of my exhaust pipe - I'm not burning oil, I think it's running rich. I'm gettingabout19 mpg and I do strictlycity driving with an auto.The car is stock with 60k miles.

- Would it be a good idea to replace the first set of O2 sensors whenI do the longtubes?
-I'm going with an o/r setup, so does itmatter if I replace the rear O2 sensors?
- Would this this help the problem... if not, what else.

 

I ran rich for alittle whileafter i got my longtubes on, then my front O2's went out. I would wait and install the new ones till after the install.

 

Yep, yep... will do. I think some of the soot came from a misfire I had a while back. I cleaned the tip with carb cleaner today so I can get a better idea of how things are going.

I keep on reading posts where people are getting like 300 mi per tank... I assume that is highway driving. Just wondering tho,is 19 mpg for an auto doing only city driving bad??? I fill upwhen I'm down to around 1/8 of a tank... usually have gone about 220 miles.

 

I'm getting 300+ a tank on mixed driving.

 

I got 350 miles out of my last tank, strictly highway, for work. It's the most I have ever gotten. I need to get an alignment and replace my front hubs, and i think that'll help a little bit