Had my H/C/I car tuned wednesday, 424 rwhp, 395 rwtq with a SD tune. Drove the 95 miles home with only a few noticeable issues. Idle will drop to 400-500 rpms before climbing back to 850-900 and some sputtering between 1800-2000 rpms, in any gear. It's a big cam and I'm still learning whats normal and whats not. Fastforward, today, I get underneath to change oil an filter an notice driverside cat is discolored to a blue color. Passenger cat is normal, a darker color of bronze like the rest of the system. Changed fluids and took it for a short run and alls fine except for the above issues. About 10 miles later I get home and get out to check underneath and now both cats are aglow pretty good. Park her asap and the red hot died no 10 seconds after ignition kill. I opened the hood and I'll tell you, if the cats were aglow, the headers up top had to be also. The windshield washer tank felt like the coolant overflow and the right side was just as hot. The top of the intake was almost as hot. Temps when I shut it down were 180 coolant and 205 oil with no codes, no knocking or no pinging. Plugs are TR6's gapped at .050, cats are Random Technology free-flows with about 4k on them.
Anyone else experience anything like this ??

Car's not going anywhere till I get in contact with my tuner and ... I'm not even sure if it's tune related.

 

Sounds like the cats are toast. I random technology cats on my camaro and head them replaced twice before I had no issues.

 

I dunno, but I would highly doubt that both cats would fail at the same time... I'd take it back to the tuner and have him look at it.

 

Sounds like a fueling issue causing the exhaust to overheat, this wouldn't effect the oil/coolant, but would certainly heat up any underhood components near the headers.

A large cam may need a higher idle, but a good tuner should be able to tame the idle at whatever RPM it is set to, and it cetainly shouldn't sputter once it's into the RPM range.

I would think the cars tune needs to be re-looked over, mind sharing were the car was taken?

 

If it's running rich it can cause problems with the cats.

 

Sounds to me it's running lean. Too rich shouldn't overheat the cats. If they weren't new cats I'd say they were clogged. Since it was recently tuned that's gonna be my guess.

 

You need to find out if your tuner turned off the COT (Cat Over Temp Protection). Most tuners disable this and sometimes the cats can overheat as there is no extra fuel being dumped to cool cats down when the computer senses they are running over 1525 degress.

 

 

Okay, I plan on looking at my plugs today.

I might also drop the exhaust to see if I can tell if the cats are clogging up.

My main concern now is what am I risking getting the car back to the tuner ??

Wouldn't the PCM take out timing once a lean or overtemp condition was/is present ??

Thanks for the replys........

 

It could be something else, but this is most likely your problem.

 

If my idle and rpms were messed up I wouldn't leave the tuner.

 

The COT shouldn't be the cause of the problem, although having it disabled would allow the cats to overheat, but the question is why are they overheating in the first place?

Again, to me, this sounds 100% like a fueling issue, call your tuner and update him.

 

Wednesday afternoon, high 40's, low 50's and raining. After 6 pulls on dyno and one last test drive, I was told she's good to go. 1st time thru the gears, I get the issue at 18-2200 rpms. 10 miles at 1st toll booth I get the idling down issue. Get home 2hrs later with just those 2 issues.
I called the shop back on friday to see about a follow-up visit and this will be handled tomorrow since tuner was out on the road...no problem.
Since then I noticed the issues with my cats in meltdown mode...

Now this morning I checked my spark plugs and they look pretty clean. I fired up an left car idle till about 165 water temp when it now will drop down to 400-500 rpms and then pick back up to 900 rpms. It'll do this now every 45 seconds or so. Didn't do this last night. No current codes, just PCM P0102, BO-RFA U-1016, U-1064, U-1096...all history.
Just went out and checked battery terminal connections, rechecked fasteners for the intake and throttlebody and all are solid. I cleared history an all I get now is P0102 and I'm MAF delete after a SD tune.

At this point I'm all ....

 

I agree having it disabled probably isnt the root cause so id look elsewhere. The COT enabled would help cool them, but like said above probably isnt the main cause as they shouldnt be overheating in the first place.
Not sure why you decided on a SD tune on a NA car. The problem is in the tune somewhere, especially with the few mentioned problems you already are having on the drive home.

 

i had cherry red glowing cats on my '94 camaro. for some reason, i was convinced they were clogged up. not the case. it was leaning out.

 

The SD tune was recommended since it's a fairly large cam for a 346.

Whiplash cam, PRC 243's stg 1, ported 92 FAST, LS2 VMax tb, Yella Terra ul's, 42lb racetronics, Powerbond 25% ud pulley, Dynatech LT's, Textrallia 0700 zgrip, TTI's, Callaway Honker

 

Hey legman, post your original opening comments on your problem over in the C5 FI/nitrous section. Lots of us tuner guys over there and someone might be able to help you out since a lot of guys over there run SD tunes while Aa lot of big cammed cars dont run SD tunes and you might run better without one. In the mean time email your tuner and ask him to email you the tune file and some of us might be able to take a look at it and might see something in it that isnt quite right. Some tuners dont like sending out a customers tune file but since you paid for it technically its your file anyway.
You could also register over at HPTuners on their forum and post the comment there as well in the appropriate section altho you would have to post your tune file there for anyone to really diagnose the problem..

 

Good info-I'd never heard of that function on our cars.

 

okay, will do....thanks