Catalytic Converter 07 GP GT?

**Gratefuldiver** · 08-03-2015

I started up the GP yesterday and had the Cat code per the dealer. Dealer says they don't do them there and the local shop refuses to use anything except OEM on SC engine, which is $905 LMAO. They cleared the code and I guess Ill see if it comes back. My question is the muffler guy full of ****? I see Magnaflow has a direct fit SS for under 300 on Summit http://www.summitracing.com/parts/mp...del/grand-prix Anybody have anything they can add here. I have the code written down but my wife took off with the car to complain to the dealer because we just bought it a week ago.

Thanks

**Gratefuldiver** · 08-04-2015

I see ZZP makes a downpipe with cat for less then the MagnaFlow http://shop.zzperformance.com/store/...Downpipes.aspx Can anyone add anything about that pipe for use with SC?

**Scottydoggs** · 08-04-2015

your gonna get a cat code with that dp or any other aftermarket cat. you need a oem cat to avoid that code.

its cheaper most of the time to hit a shop and have then cut the old one out and install a new one. as long as its not high flow it should work.

**Gratefuldiver** · 08-04-2015

Originally Posted by ScottyDoggs

your gonna get a cat code with that dp or any other aftermarket cat. you need a oem cat to avoid that code.

its cheaper most of the time to hit a shop and have then cut the old one out and install a new one. as long as its not high flow it should work.

Even with that 90 bung extender? 07 is the cut off for emissions in IL so a code would be a bad thing. I may just wait to see if it comes back. I had it up to about 120 right before it threw the code lol.

**Scottydoggs** · 08-04-2015

in the 01 up cars it turns into a over fueling issue. not sure if you can even tune out the cat in a 07.

**J57ltr** · 08-04-2015

That and 05' and up have a weird test where they constantly test that the rear O2 is working properly. You'll see your vacuum go from about 18-19 down to about 10-12 for for a second. If you are also watching the O2's you will see the change as well. Scotty, how do us guys that want to run more ponies get a cat that is both high flow and compliant. Say if you are going to a 3" exhaust use a Carb compliant 4" convertor?

Jeff

**Scottydoggs** · 08-04-2015

its one of them things. dhp can shut all that off in a 3800 up to a 05. thats where dhp support ends. htp cant seem to shut it off like TT can.

im not sure if the 3 inch cat will work or not. it would still need to be oem style and not hi flow, thats for sure.

**J57ltr** · 08-04-2015

End up putting 2 in parallel lol. I am really going to have to read up on all these different tuners, I'm way behind the power curve.

Jeff

**Gratefuldiver** · 08-04-2015

This is the part I love. The vendors say there "high flow 400 cell cat does not throw codes" but people with actual experience say the high flow unit do throw codes. I tend to lean more towards real world experience

I see Stealthee is using a 3" ZZP downpipe with cat on his 07 GP GT. Maybe he will chime in on the subject.

**blueguy** · 08-05-2015

It's hit and miss with the cat code.

I didn't get one in my GXP.

And it's an '05. Catted ZZP one. If you're worried about it, then get a factory replacement. I'd take my chances with a downpipe thats a quarter of the price than what a shop would want with parts and labor.

**BillBoost37** · 08-05-2015

Or .. have someone like OverKill tune you a pcm with it removed.

**Gratefuldiver** · 08-05-2015

What's the turn around time on something like that?

**BillBoost37** · 08-05-2015

No idea.. I tuned my own stuff. But a call or email to the vendor would probably get you the best info/answers

**J57ltr** · 08-06-2015

Originally Posted by Gratefuldiver

Even with that 90 bung extender? 07 is the cut off for emissions in IL so a code would be a bad thing. I may just wait to see if it comes back. I had it up to about 120 right before it threw the code lol.

So 8 years old is the cutoff for emissions testing in IL?

**blueguy** · 08-06-2015

Sh1t, we just give someone $20 here.

No one gives a **** in BFE Mizzery.

**J57ltr** · 08-06-2015

Can't do that in H-Town they have installed cameras on the machines now and you have to read the bar code of the car being smogged. I am just surprised in such an oppressive state as Illinois that 8 years would be the limit. Here it's 24 years. That's why I'm concerned about a cat that will pass emissions. I am going to end up with headers and could fab up a stock flanged cat for use when getting the car inspected, and a regular cat for normal running or just a pipe. They on;y really check to see if the check engine light is on and use a sniffer and do a 25 mph and 35 mph dyno test.

Jeff

**blueguy** · 08-06-2015

That's insane.

I wish every place was like Kansas when it comes to this stuff.

You take your car for an inspection when you first buy it, and then after that they don't give a flying crap. They just send you plate renewals every year. I see Kansas cars running around without windows, no exhaust, missing body panels, wheels wobbling looking like they're about to fall off, etc.

**Scottydoggs** · 08-06-2015

NJ looks for the cat with a camera they drive over, but thats it. they dont seem to care if its hi flow or not. as long as its there.

and the cel is off and all systems show ready.

**J57ltr** · 08-06-2015

In Texas you don't have to have a windshield but you do have to have wipers for your safety inspection. You gotta remember we have a lot of uninsured, undocumented people running around with cars that are a hazard on the roads. When I used to have my SC I had 2 1/2" cats into a dual in single out resonator then 3" to the rear muffler and I never had a problem passing smog even without a tune and using a C&L MAF to compensate for 42# injectors. I had changed up everything except the short block and never failed emissions. If I had it now I wouldn't even have to have it smogged, but parts were getting scarce and I needed a 4 door so away it went. I don't mind smogging the car and If I get the Rear O2 turned off I shouldn't have any issues, since it's only once a year, I'll just switch out the Cat when needed I guess if there isn't an alternative with a high flow cat that will pass.

Jeff