Intermittent missfire
 

Recently I have been having a intermittent missfire since I relplaced my o2 sensors. The car would start idling a little rough. Now and then it throws up a o2 sensor code, I clear the code and it starts running well again. How ever 2 things confuse me, previously when my o2 sensor failed it didn't effect the way the car idled. Also a weird code came up the other day P1614 - fuel control module fuel metering module. I changed the plugs, car was running great now it's come back again and my o2 sensor code is popping up again. Main issue is it's idling rough and on cruise has a little hesitation. Also when this happens it runs rich. Anything I should get the dealership to look at or look for?

Thanks
h

What code is O2 sensor?

Did u change bOth o2's or only 1.

Could it be your tune giving false codes like mine did?

I had P2196 O2 Bias/struck rich for a while before car had misfires.

Have you filled it up with a different type of fuel recently?

Replaced both o2 sensors about 1000kms ago. Tune is MHP. I honestly don't believe it's the tune because under WOT the car still rips! I have had a previous fuel issue which I addressed.

Code p2237 just came up, cleared it and it started running mint again. I'm highly assuming it's the o2 sensor causing it all

Have u had your car in the dealer with the tuned ECU?

Yes I have. They've known about since day 1.

Ok so that code p1614 came up again. It's something to do with the fuel system. No idea which part, then I got hit with a missfire in cyl 1 and 4. Cleared codes drove it straight to my dealer, should have some news tomorrow. Could be bad fuel again, hope not.

I would have the dealer flash it back to stock to see if the problem goes away.

spark plugs!

Spark plugs changed less then 200kms ago and def not them. The car was running mint and hammering! This just happened yesterday and today.

Mthis, I don't think that will do anything as the car has been running perfect up until recently. No issues at all with it.

Remember the issues I had. 2 new fuel pumps and a new battery and till throwing codes, in the end I re flashed it back to stock and the problems went away. I am not suggesting that your tune isn't right but it is worth a try. I think sometimes the tunes give false codes. Send your ECU to Sonny, best thing I ever did.

Multiple cylinder misfires in the same bank is most likely an o2 sensor issue. Funny how everyone that I have talked with who has dealt with this issue seems to have problems with 1-4?

The only reason why I disagree with it being the tune is, when I had the BPS issue I didn't have this problem. I've had the MHP tune for 3months now, and it just happened. I will only reflash it to stock as my last resort because nothing is pointing to the tune. The issues you and I had with the bps tune was the same, since mhp tune all of those have been rectified.

Hughes, I wonder why? My o2 sensor code says bank 1 sensor 1 from memory.

Looks like we may have found the issue, o2 sensor upstream

Congrats!! My issue, documented in a different thread, had the same resolution. The codes don't simply say "up stream O2 sensor" but point at other afffected items. While I was having this problem, the plugs from that cylinder bank all fouled as well making the diagnosis even more difficult. Keith's MB ace noticed irratic voltage coming from the problem sensor even though it was telling the computer all was fine. Once replaced I have not had a problem since.

PS: My car had gotten to the point where it was not drivable so this is not just a convenience issue.

Similar problem
 

I had a very similar problem.......mine had to do with the ignition module (voltage transformer) that works with both ignition coil packs being bad and fouling plugs on the one side......dealership read the codes.......

Well so far so good! Tomorrow I will be driving it more so over the weekend I will see how it goes otherwise pleased to say all is well now

sorry for bringing up an old thread but I have this p1614 code and was wondering if the o2 sensor was your fix to that code

Hey bud couldn’t tell you
i was reading through this and i actually don’t remember any of it as it’s been so long
And my car has taken a completely different direction now

if not referencing the codes, these symptoms are usually an issue with 1 or 2 primary oxygen sensors being faulty.