1996 850 Turbo misfiring

iamdadog · Post by **iamdadog** » 27 Feb 2017, 22:04

I have a 96 850 Turbo. Here's the codes it's throwing:

P0300 Random Misfire Detected
P0301 Cylinder 1 Misfire Detected
P0304 Cylinder 4 Misfire Detected
P0133 O2 Circuit Slow Response (Bank 1, Sensor 1)
P0137 O2 Circuit Low Voltage (Bank 1, Sensor 2)

I've replaced spark plugs, as Auto Zone recommended (plus it was exceedingly cheap to accomplish).

Anyways... no help. What's going on here? Could a faulty oxygen sensor be causing this?

Post by **shaker_chi** » 27 Feb 2017, 23:20

I'm assuming since you went to Auto Zone you did not get OE plugs. These cars, especially the turbos are very particular about their plugs. If you don;t want to spend the cash on OE, your 2nd best bet would be copper. Also, check your spark plug wires. If they are original I would suggest replacing with either OE or the IPD 8mm versions. Do you get multiple misfires? Does your CEL light flash when you accelerate or put a load on the engine? Have you tried to reset the CEL since you changed out the plugs?

iamdadog · Post by **iamdadog** » 27 Feb 2017, 23:29

I got NGK copper plugs... I gapped them reasonably well, to .028 inches.

I haven't checked the wires, will do that next.

The misfires seem to happen when the engine is cranking? It is a really rough start from cold... after starting engine seems to run smoothly.

The CEL does not flash at any time during the operation of the vehicle.

I disconnected the battery for 1.5 hrs after replacing the plugs... the CEL seemed to be off when I tried to start the car, then turned on again during the start (which was still rough).

Post by **tryingbe** » 28 Feb 2017, 06:18

What's the compression? Start there.

Post by **theWIFES_S70** » 28 Feb 2017, 10:11

How's your cap and rotor? Sounds like it could be something in there that "smooths" itself out once you get rolling...