Originally Posted by yournan

Ok took my st170 up shakespeare raceway yesterday and I couldn't get under 17, yet last time I got 16.1! My fastest time was with the cat on, so not sure if the decat is costing me time, or the below problems. I think its the below problems.

Now lately it has been flat at the top end in second and first gears, though third storms on. I checked the dsi 6 months ago, so that is my first port of call. However the engine light has been on for several months with the below errors:

P0135 O2 Sensor Heater Circuit Malfunction (Bank 1 Sensor 1)

P0141 O2 Sensor Heater Circuit Malfunction (Bank 1 Sensor 2)

I have replaced both 02 sensors and cigar, I have removed the 02 cheater as I have a decat on and nothing. The cables and looms have been checked and they're ok. Its doing my nut! So I'm not sure if that would be holding it back, I don't think it would be doing it any favours.

Also with it being flat at the top it start stuttering on the way home. Though later that night was fine. I guess if it was the old cracked fuel pump it would be like it all the time - perhaps something is still in the tank or fuel lines?

It also has been like kangeroo'ing sometimes, as if the coil pack is going, but then perks up. It hasn't done that for two weeks and only come on in the rain.

Last oil change was about 6k ago, plugs and leads done at the same time. Fuel filter was done about 30k ago.

Help would be appreciated as I'm gonna sell the bloody thing or push it into a pool!

btw - it has been mentioned could be corrupt ecu, although I have seen this error occur when someone's front loom got chopped up in the fan, but mine looks ok.

Mercer