sj6sp

Its a long shot it has a faulty connection...all 4 O2 connectors are on the pass side firewall. don't know which one it is.

BUFFALONOGAROpebFATS

02 sensors are messed up, but might not be caiusing all the problems. adjusting with lemi might only bandaid the problem, but wither way he shouldnt have to adjust the car at all.
if you changed the plugs, then it might be the "rubber dick" as i call it that connects the coil to the plug. there is no way to inspect them, so swap one from a bad cylinder into one thats not getting any of those misfire codes. if it transfers then you have the cluprit, and i think they are like 8 bucks at the dealer.


good luck

E Vader

Bad O2s or not raising the idle is usually met with a smoother idle condition (20-40rpm). The S4 is known to have consistent missfire issues even when running "well". In the past fouled plugs or plugs that were not "hot" enough were the issues that I found here.

E Vader

Even if your car were runnning perfect this would "smooth" things out....IME.

BUFFALONOGAROpebFATS

oh ok, i thought you were trying to suggest that as a permanent fix

jayk_S4

I got 0% on both with part throttle, but do you have to be moving to get the part throttle readings?

I also did a little logging of 032 and 033 (don't know what it is but seemed to be giving weird numbers). 032 never changes from the .2% and .4%, here's 033. Is there a more useful way to log? I was expecting to get rpm readings like some other logs I've seen on here.

0 -2.3 0.155 2.3 0.64
0.3 -3.9 0.555 1.6 0.63
0.6 -3.9 0.71 0.8 0.555
0.9 -4.7 0.71 0.8 0.57
1.21 -5.5 0.665 0 0.5
1.5 -5.5 0.635 -0.8 0.185
1.8 -6.3 0.645 2.3 0.075
2.11 -4.7 0.11 3.1 0.07
2.41 -3.1 0.095 3.9 0.06
2.71 -2.3 0.095 4.7 0.07
3.02 -1.6 0.1 5.5 0.075
3.32 0 0.1 7 0.075
3.62 0.8 0.11 7.8 0.08
3.92 2.3 0.125 8.6 0.075
4.22 0 0.73 10.2 0.08
4.52 -1.6 0.725 11.7 0.08
4.83 -3.1 0.73 13.3 0.14
5.13 -4.7 0.7 10.9 0.69
5.43 -6.3 0.71 10.2 0.69
5.73 -7.8 0.695 8.6 0.71
6.03 -9.4 0.675 7 0.665
6.33 -10.9 0.51 5.5 0.645
6.64 -7 0.165 7.8 0.1
6.94 -11.7 0.655 10.2 0.11
7.24 -7.8 0.145 9.4 0.635
7.54 -11.7 0.635 6.3 0.7
7.84 -10.9 0.7 3.1 0.67
8.15 -13.3 0.665 0.8 0.67
8.45 -11.7 0.1 -2.3 0.595
8.85 -14.8 0.66 3.1 0.105
9.15 -11.7 0.1 3.1 0.325
9.45 -8.6 0.225 0.8 0.595
9.76 -12.5 0.69 6.3 0.3
10.07 -7.8 0.21 5.5 0.13
10.39 -13.3 0.46 0.8 0.66
10.7 -12.5 0.715 2.3 0.485
11.02 0 0.075 0 0.695

jayk_S4

any ideas? i'm on vacation but will probably order an o2 sensor and try replacing it when i get back

jayk_S4

I replaced both pre-cat o2 sensors, sparkplugs, but still get constant misfires on cylinder 4 and random misfires on cylinder 1&5. I switched the coilpack and connector-thing with cylinder 6 and the misfire still happened on cylinder 4. I almost gave up, but then decided to try switching the two things on top of the airbox (switched the chips, not the wires) and the misfire moved to cylinder 1. So I assume one of the POSMs is bad...

Anybody agree/disagree? Also, any idea where to buy these things?