Burning Smell after O2 Sensor Replacement

[bluesharks117]

As a few of you may have read my older posts about restoring my corolla's MPG, I now ask help about a concern. First off, I cleaned the MAF sensor to see if that is what it will take to improve my car's MPG. I didn't notice too much of a big difference, maybe a 2-3 miles more per gallon. So I decided to replace my O2 sensor (pre-catalytic). It went fine. I started up my car and noticed some smoke coming out and a smell like something was burning. No check engine light came on but I turned my car off immediately. I checked around to see where it came from but I couldn't determine it. I started my car again and this time no smoke came out but the smell was still there. I turned the car off, waited a few hours, and drove for a few minutes on the road. The car felt great like it had a little more power. I was very pleased. Still there was no smoke. I came back, turned the car off, and still smelt that scent like something was burning, but it wasn't as intense as the first time. What is going on? Is it just the new sensor getting adjusted? Will this smell go away? I need your help guys. I don't want to be driving around in a time-bomb.

[landphil]

It sounds like oil residue, etc from manufacturing that's burning off the new sensor, plus any anti-seize you used (or should have used) on the fasteners that's burning off. A good, hard run up a long hill should cure it, or it will disappear on it's own. Just make sure you didn't leave a rag, 1/2 a beer, you neighbour that came to help, or anything else sitting in there.

[Kyle Hamelin]

Put some new iridium spark plugs in and put a bottle of fuel injection cleaner when you fill up next. also new air filter those three right there should give you better mileage.