Running rich?

[Unit 5302]

Go back to a 180-195* thermostat. Look up Rebel 79's off road H pipe fix.

Most likely what is going on is your car either isn't heating up fully so it's staying in open loop, or your O2 sensors aren't getting a good read on the exhuast gas because the velocity is too high with that h pipe. Adding a small tab right in back of the O2 sensor is a way to slow the gases down a little bit. Quite a few people have benefitted from that trick Rebel 79 came up with.