Headers could melt plastic if close enough. And they're known to be a hazard for plug wires. Wrap your headers?

Catalytic Converters burn unburned fuel without a spark. That burning (catalyzation) generates heat just like combustion would. If you're running really rich (or dumping unburned cylinder charges due to misfire), that raw fuel will get the converters so excited they'll heat up until they melt down. You replaced the Cats? Misfire came back? You probably have to replace them again.

Except. Emissions regulations require the ECM be able to detect misfires. If you're feeling something misfire-y while driving and you're not getting a check engine light, it may not be misfire.

 

Headers could melt plastic if close enough. And they're known to be a hazard for plug wires. Wrap your headers?

Catalytic Converters burn unburned fuel without a spark. That burning (catalyzation) generates heat just like combustion would. If you're running really rich (or dumping unburned cylinder charges due to misfire), that raw fuel will get the converters so excited they'll heat up until they melt down. You replaced the Cats? Misfire came back? You probably have to replace them again.

Except. Emissions regulations require the ECM be able to detect misfires. If you're feeling something misfire-y while driving and you're not getting a check engine light, it may not be misfire.

Hey RocketSlet,

The high flow cats were hollowed out after last year. I have considered wrapping the headers and might go that route. As for check engine lights, I asked the tuner about this and they had disabled misfire detection due to the cam install. It does run rich and did so even before any modding and tune as evidenced by black smoke on hard pulls. I'm fairly sure the wires got damaged again due to heat, last year they replaced with MSD's.

Thanks

 

easiest to find is the mishimoto aluminum coolant overflow tank fit for gen6 camaro, but is the same. no exp with it myself but its just a tank im sure its fine. i think moroso makes one
need to also secure wiring harness that runs under the coolant tank as far away from header

wrapping the headers and also using plug wire sleeve would be a good idea, if you can keep the MSDs off of everything theyre ok - ceramic booted wires if/when they start to go i've had better luck with taylor spiro wire ceramics

what spark plugs are you running (heat range)? if its building that much heat could be glowing/dieseling the plugs. i would double check on the misfire detection info - usually de-sensitize the knock sensor some with cam/headers. never heard of disabling misfire detection. i've ran into if the torque tables are not set up correctly and on MAF it throws abunch of misfire counts out, swap it over to speed density and no other changes and they all go away...not to say swap over to speed density, make sure your tuner is capable of correctly adjusting the torque tables

the excessive black smoke on these with stock tune is the cat over temp, mine did it horribly after a single WOT pull.

 

Thanks for the reply randeez, I've read good things about the Taylor wires and might try those. The spark plugs are NGK Iridium's do you recommend another plug? I'm going to take my car into the shop in a few weeks and will discuss the tune and see if he can work on the misfire tables instead of disabling.

 

You shouldn't need new plugs. And you can't get a better plug than an Iridium plug. Iridium is a "rare earth metal", very expensive, but they use it because doesn't "cook off" like a steel electrode does. A set of Iridium plugs should easily last 100K miles. Too rich/fouled? Clean 'em. The only way you can really ruin them is by running too lean.

 

the iridium plugs are fine, but what i mean is the plug itself has a heat range spec, stock lt4 plugs have a heat range of "5".
with nearly 700whp i would be running a plug with a heat range 7, ngk 6510 or similar

 

the iridium plugs are fine, but what i mean is the plug itself has a heat range spec, stock lt4 plugs have a heat range of "5".
with nearly 700whp i would be running a plug with a heat range 7, ngk 6510 or similar

I'll have to follow up with the shop but assume they used the 6510's as they do a ton of LT4 work on mostly Camaro's and Vette's.