problem with my brothers e36 first time posting and would apreciate some advice!

[dlane3128]

So my brother has a 92 325i. The problem started when he had a new flowmaster exhaust put on, after that the car stalled and would not start multiple times. After checking a few things out I noticed 3 of the four wires on the o2 sensor had been broken. So we headed to autozone to replace the o2 sensor. The car ran fine for the first day but then started to have a very rough idle which some times even causes the car to stall. My normal thinking is that it started when the exhaust was added so the problem is there but I cannot seem to figure it out, a bmw mechanic spoke to me about the importance about using bmw o2 sensors but I was not sure if he was just blowing smoke up my a$$. Thanks for any advice you can give my lil bro is a car newbie so I will be driving 4 hours tomorrow to help him fix it.

Thanks everyone!:mad:

[Mary99]

.....bmw mechanic spoke to me about the importance about using bmw o2 sensors but I was not sure if he was just blowing smoke up my a$$. ...

It's true, the O2 sensors control gas/air mixture for proper combustion. One pre cat and one post cat. They should always be replaced in pairs, otherwise the degraded signal from the old one will ruin the new one very quickly, especially if it burns rich.

Good Luck

[Bimrpwr]

you can use a generic o2 sensor with no issues. He is just mad that you did that and saved some money. The problem you are having is nothing to do with the new muffler. I would put the old o2 sensor back in and splice the wires back to gether and drive for @100 miles so the car can relearn itself with the o2 sensor. Or buy a OEM one for the @80 dollars and put that in. ALso check all vacumm hoses as well. Are you getting any CEL lights??

[Bimrpwr]

It's true, the O2 sensors control gas/air mixture for proper combustion. One pre cat and one post cat. They should always be replaced in pairs, otherwise the degraded signal from the old one will ruin the new one very quickly, especially if it burns rich.

Good Luck

He only has one o2 Sensor. 328's have the pre and piost cat ones. 325's dont. they just have one precat. right at the y connector.

[Mary99]

He only has one o2 Sensor. 328's have the pre and piost cat ones. 325's dont. they just have one precat. right at the y connector.

thanks. :thumbup:

[bboyvek]

correct me if im wrong but i thought all obdII bmw have multiple o2 sensors up to 4 i believe. and the 325 being a obd1 car only has one. (they stopped 325 production after 95 so i believe all 325 should have only 1 o2 )
or i got it all wrong??

[Bimrpwr]

correct me if im wrong but i thought all obdII bmw have multiple o2 sensors up to 4 i believe. and the 325 being a obd1 car only has one. (they stopped 325 production after 95 so i believe all 325 should have only 1 o2 )
or i got it all wrong??

they did not stop the 325i production after 95. They were made up to 8/2006

the car is he working on is a 92 which is a OBD1

[bboyvek]

well i was talking for the e36 chasis they did stopped the 325 after 95... and brought into play the 323 as the new 2.5 engine afterwards..

[dlane3128]

im sorry i must have rushed my post, there is a check engine light on also that is saying the thermostat temp. sensor is broken but the temp. is working fine.

[Bimrpwr]

could be the temp sensor. It is hard to say but try to replace that..

[ColumbusBMW]

It's true, the O2 sensors control gas/air mixture for proper combustion. One pre cat and one post cat. They should always be replaced in pairs, otherwise the degraded signal from the old one will ruin the new one very quickly, especially if it burns rich.

Good Luck

I believe that the 92 only has 1 post cat O2 sensor. I see this has already been addressed. I would say try cleaning the ICV.