Hey all, new guy here.
I bought my Fit about a month ago, thought I got a good deal, but turns out I was a bit mislead. ~130k miles. It has a clean title, but now that I've been in it more there are definitely signs it was in a wreck at some point. My main concern right now is that I keep getting a downstream O2 sensor bias stuck lean code. I replaced the sensor with an OEM sensor hoping it would fix it, but no luck. It will run about 3-4 on/ off cycles after clearing the code before it comes back. This week I tried checking the exhaust system for a leak, but couldn't find one. Then I adjusted the valve lash, and replaced the spark plugs, still no luck.
Before valves and plugs it was getting about 30-31mpg mixed driving, now 31-32mpg. I feel like it is dumping more fuel because it thinks it is lean because I thought mpg should be a bit better.
What am I missing, or what else could it be? Thank you for your help.