3-Series (E46, E90)Chat relating to the BMW 3-Series from 1999 to Current. Models include: BMW 316i, BMW 318i, BMW 318Ci, BMW 320i, BMW 323i, BMW 325i, BMW 330i, BMW 328 Ci, BMW 328i, BMW 325i/xi, BMW 330Ci, BMW 320d, BMW 330d, BMW 335d.
Hey everyone, I've posted on this before, but didn't receive much help. My car has been issuing the fault code "O2 sensor adaptation limit", apparently running either rich or lean, but I can't tell which. I also don't know what would be the most likely culprits.
I've just replaced the spark plugs with Bosch +2's and cleaned the air filter. I performed a Hot Soak about 2,000 miles ago, when I last changed the oil as well. I previously had an error for the secondary air pump, but that has since vanished. I'm not receiving any other errors; no misfires, no O2 sensors malfunctioning, etc.
I have inspections within the next week and am concerned I'll be running outside of the specs. Any recommendations for either a legit trouble-shooter or temp solution to pass the inspections?
Any thoughts out there? I've heard head gaskets and O2 sensors are other options to try to bring the A/F ratio back up to spec. I have almost 80K miles on the car. Should I just bite the bullet and get the new O2 sensors?
Originally posted by Hootie361@Aug 24 2005, 08:11 AM Any thoughts out there?* I've heard head gaskets and O2 sensors are other options to try to bring the A/F ratio back up to spec.* I have almost 80K miles on the car.* Should I just bite the bullet and get the new O2 sensors?
There is the electronic tool , which fast and easy checks status and performance of oxygen sensors. Basically automotive manufacturers recommend change them around 60 000 miles/ 100 000 km. My friend made more than 130 000 mles and sensor is still pretty good after checking it out. Perhaps before you change them, check them first( you need 4 of them-$100 plus each!). Good Luck!
Thanks Zibby. I've priced my sensors before, so yeah I know it'll run me about $400 to replace them all. I used a Chevron FI cleaner in my gas tank this past week to see if that would make any difference (the assumption being my FIs were clogged). The SES light went off a couple days ago, but the error code is still stored in the computer. I'm going to give it another day or two, clear the error codes then see if it returns. Here's hoping a $12 bottle of fuel additive solved my problem.
Update: That solved squat. Next step is the fuel filter. After that, I'll have a local shop test my O2 sensors individually. If all that checks out and I still have the problem, I'm afraid I might need to replace my cats. Any recommendations on websites that sell cats for an E46?
Different user name with the change in the website. Had trouble logging in under the old UN... anyways...
So I ran a compression test and all cylinders were hitting about 180psi +/-. So I can eliminate any cylinder related problems. Damn. I really don't want to spend $400 to replace my O2 sensors only to discover it was the fuel injectors!!! Anyone have some "old wives" tests to know the difference?
And 10,000 miles later, the conclusion to this problem. Turns out my air intake boots were rotted through. The BMW tech found the problem after running a diagnostic. Replacement parts ran $20 for each of the 2 boots, took about 1.5 hours to replace. FYI, the pipe clamps are in ridiculously difficult places to reach. I highly recommend cutting the old rubber intake boots into tiny pieces with a sharp razor, then peeling them away.
Guess I should go have that inspection done now, eh?
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