can not clear codes

[SCGTP]

i can not clear some codes that have just occurred. can anyone give me some advise?

getting on the highway yesterday i got the flashing ses light. after a few minutes it remained on.

using a predator programmer the codes are

1. p0300 random/multiple cylinder misfire.



2. p1554 cruise engaged circuit high voltage
3. p1860 tcc pwm solenoid circuit
4. p0420 catalyst system bank 1 eff below theshold.

the predator could not clear these codes and disconnecting the battery did not work. slp headers and cat, intense level 1 kit with a 3. inch pulley. the car is running fine.

what could be causng these codes?

thanks

[Scimmia]

The P0420 is because of the high flow cat, nothing new there. What does the Intense Level 1 kit mean? If it's got a cam, that could cause the P0300, although it should throw it at idle, not on the highway (flashing MIL means misfire). The P1554 would seem to be a wiring issue, but I've never seen that one before, so it's hard to say. P1860 means the torque converter solenoid isn't doing it's job. I'm pretty sure it could be the solenoid, a valve, the clutch itself, or a few other things.

[SCGTP]

intense level 1 is a reprogrammed computer, kn filter and 3 pulley, colder plugs.

the car has about 62000 miles and is not abused, much.
stock cam

how can these be corrected?