99 S80 T-6 cylinders 1-3

ToddMc · Post by **ToddMc** » 22 Apr 2011, 08:17

Spark plugs in Cylinders 1-3 carbon up and foul.

Cylinders 4-6 burn clean.

214,000 miles on engine.

Has O2 code.

Fuel rail pressure in 60psi.

Is there a separate Spark control module for cyl 1-3 and 4-5?

Post by **jimmy57** » 22 Apr 2011, 08:41

no but the fuel mixture is controlled in two groups, cylinders 1, 2,3 and cylinders 4,5,6.
The O2 sensor is the clue here.

Post by **JDS60R** » 22 Apr 2011, 09:07

Time to change the oxygen sensors . What code did you get exactly??
Please use Matt's link and buy the direct fit Bosch from Amazon. You will save a bunch and they come very quickly.

Post by **boosted5cyl** » 22 Apr 2011, 12:23

Yeah might be a lazy O2 or bank 1 just stuck in open loop.