I´ve got an issue with my 1996 328i OBD I (European spec). Almost a year ago I plugged INPA to my car and pulled a error code "25 Lambda probe heating Probe 1". Analog Values 2 graphics showed that, while oxygen sensor 2 voltage oscilated between 0-5 V, oxygen sensor 1 voltage always stayed in the 4,80-4,90 V range. The car drives fine (although since I bought it 4 years ago the engine, frankly, doesn´t seem anywhere as creamy as I expected a in-line six should be, or as my E39 530i), idles perfectly, good performance and fuel economy.
Yesterday I had the annual inspection and it failed the smog test, the CO values were very hign and worse in the second try than in the first one. This afternoon I´ll plug INPA again but it seems the oxygen sensor 1 need replacing.
Question is, is it advisable to replace both oxygen sensors or replacing only the bad one will be enough? OE BMW or a NTK sensor is fine? Very difficult to do? I suppose that if it´s screwed in the header the cold/hot temperature changes will make it hard to remove.
Thanks a lot.
Yes replace both, NTK/NGK/Denso. It's not a hard job, but there is a tool that assists in getting the old part out. You should also use injector cleaner every so often. Here in the US we have a product called CRC GTP that will help clean the system out (crc guaranteed to pass, google it). If you can't get it then just run a quality product over a couple tanks of fuel, use good gas. You should drive a couple tanks of gas with cleaner before re-testing.
- - - Updated - - -
search ebay "oxygen sensor tool". I don't know what size it is though.
Attn. NEWBIES: Use the search feature, 98% has already been discussed.
Click the search button, select "search single content type", select the "e36 sub forum" specifically, try the "search titles" then try the "search entire posts".
We have CRC products over here but I´ve never seen CRC Guaranteed To Pass for sale. I could try and use a good injector cleaner like Liqui Moly´s, and see if I´m lucky in the smog test, but if it fails I would have to pay the inspection test cost again. It´s not very expensive but it´s about half the price of a new NGK oxygen sensor, so the sensible thing seems to replace at least the bad one.
Thanks!
New oxygen sensor installed, I passed the smog test with flying colours. Great!
Bookmarks