If a o2 sensor is bad will it throw a code?
Thread Starter
Melting Slicks
Joined: Apr 2008
Posts: 3,131
Likes: 12
From: Houston Tx
If a o2 sensor is bad will it throw a code?
I have 90K on my car and starting to wonder if my o2 sensor could be bad. My mpg is starting to decrease and can barely push out 270 miles per tank. I use to get around 315 or so. I only have the two sensors now due to the LG Street LT header install. Would replacing these fix my MPG or do they even need to be replaced since no code is being thrown? Or maybe I could take them out and sand them down to clean it a bit?
Safety Car
Joined: Nov 2000
Posts: 4,549
Likes: 30
From: Shenandoah Valley Virginia
Did you get the car tuned after the header install ?? Major airflow differences that could change mileage happen with headers and eliminating the second set of 02's. O2 sensors will set DIC code when they finally fall beyond acceptable operation range or fail. They tend to gradually degrade over the life of the sensor, at 90K you are due. NO way to "sand" or clean units, you have to replace, they are not that expensive. IMHO bottom line get new sensors and a quality tune to fix your problems.
Thread Starter
Melting Slicks
Joined: Apr 2008
Posts: 3,131
Likes: 12
From: Houston Tx
Yes the car was tuned about 3 years ago when I put the headers in. Dyno tune at that. Which sensors do I buy? If I do recall LG recommend to move the rear o2s to the front and do without the fronts. I also have no cats.
Le Mans Master
Joined: Jun 2009
Posts: 6,528
Likes: 752
From: South Dakota
This spring I had an O2 code (P0133) which was an O2 slow to respond. When I replaced it, there were no more codes, but only very little change in mpg or performance.
I have read that they will deteriorate over time and can affect mileage, so it might not be a bad idea to replace them if you have concerns.
Good luck.
