Dreaded random misfires

[Goneau]

So I had a misfire on a cold start the other day, and now I'm having other misfires too.
I was on the highway in 6th at about 65, went pass and it kind of cut out and felt like a miss, cel flashed, checked it misfire 2 and 6.
Went to get on it a little bit, and cell flashed again. I currently have a cel for bank 1 sensor 2 o2 sensor and I got another for random multiple misfires last time I got on it a bit.
Current mileage is 98k timing was done around 65k or so, so I didn't think timing would be a concern. Coil packs injectors and plugs were done a few years back according to Carfax. Any info will help. And no I didn't do a good search yet.

Sent from my potato

[Lucca M]

Exhaust leak? It caused my engine to misfire when flex pieces went bad.

[Goneau]

Wow funny that you said that, because it does sound like I have a bit of an exhaust leak. It just got a little louder than normal lately

Sent from my potato

[Lucca M]

Been there done that. If leak is bad o2 sensors are getting wrong measurments and that might cause misfires.

[Goneau]

I assumed so, I'm doing o2 this week and possibly coil packs while I'm at it

Sent from my potato

[Lucca M]

Id check for leaks first. Maybe o2 sensors are good

[rocket5979]

Been there done that. If leak is bad o2 sensors are getting wrong measurments and that might cause misfires.

His DTC pertained to "Sensor #2" which is the downstream oxygen sensor that only monitors catalyst efficiency. The "Sensor #1" upstream oxygen sensors are what provide short term fuel trim feedback data to the ECU to assist in controlling part throttle fueling.

OP, do you have piggies on your car or are you still running the pre-cats? Also, have you looked to see exactly what cylinders you are getting misfires on? Is it located primarily on one bank of cylinders or both?

[jonjesney]

Hi Guys

I'm seeing the same thing,did you get to the bottom of this?