Catalytic converter 1997 GP GT

[olopezm]

Hi guys,

After I can figure out what's wrong with the power steering in my car I'll be replacing the cat converter because the current one installed (it's the original) is rattling (broken honeycomb) and I keep noticing a sulfur smell when the car is in the garage so I'm guessing it's time to replace it.

I remember noticing:
- The temperature in the cabin is a bit hotter than usual
- There is a sulfur smell in closed areas.
- Overall performance of the car drops a little after the engine has reached normal temp (this might not be related).
- Rattling noise only when revving the engine.
- Some bogging when starting the car.

I'm not getting any DTC's (at least yet) but I hooked my actron scanner, took a quick look at the downstream O2 sensor and it seems a bit sluggish (I know the refresh rate of the scanner is slow).

AFAIK these symptoms should be consistent with a problem with the cat converter. What do you guys think?

I've been checking for prices and found a Magnaflow 99000 for ~$140 bucks; anybody has any comments on it, has anyone tried it?

I WISH YOU ALL A HAPPY NEW YEAR!

Thanks in advance,

Oscar.

[GTP Dad]

I have a 3" Magnaflow on my GTP and it works just fine. It was welded on to the down pipe and I got rid of the U Bend by purchasing a piece of pipe with a bung for the O2 sensor. The Magnaflow is a good choice especially given the cost.

[rickisrad]

That is expensive for just the converter and no downpipe. you can get the whole assembly for $170. also if you walk into advanced auto they have the magnaflow mettalic spun converter for 90 bucks off the shelf.

[olopezm]

Originally Posted by GTP Dad

I have a 3" Magnaflow on my GTP and it works just fine. It was welded on to the down pipe and I got rid of the U Bend by purchasing a piece of pipe with a bung for the O2 sensor. The Magnaflow is a good choice especially given the cost.

Thanks GTP Dad, I wonder if you ever had a problem with any P0420 DTC? I read a couple of guys had this even with the new cat and had to re-flash the PCM in order to delete al rear cat codes. I believe Tim (tblake) was one of them...

Do you think the U-bend delete on mine would help anything being a GT? What changes should I expect?

Originally Posted by rickisrad

That is expensive for just the converter and no downpipe. you can get the whole assembly for $170. also if you walk into advanced auto they have the magnaflow mettalic spun converter for 90 bucks off the shelf.

Thanks Rick, that would be great if I was in the US but since I'm in Mexico, that's the greatest deal I can get (at least until now). Actually I think is a pretty good deal considering the first guy I asked quoted me with an "approximate" price of $228, go figure!

Oscar.

[GTP Dad]

I have had the light come on a couple of times but the O2 sensor needs replaced. I don't run the car that much so it isn't a huge issue, I have my own scanner so it isn't a problem to clear the code. The U-bend delete will free up the exhaust and is worth a couple of HP on the GT as well as the GTP. Since you are going to be working on the exhaust anyway now is a perfect time to remove it. Just don't forget to get a piece of pipe to extend the exhaust slightly and you will need a bung to weld on or a pipe that has one already installed for the O2 sensor.

[olopezm]

Thank you!

It definitely sounds like a great time to do it, like you said.

I'll make sure to post any results when I get it done. Just being curious but which model of magnaflow cat did you use?

Oscar.

[GTP Dad]

I am not sure it was put on several years ago. It is 3" in and out and a high flow model.

[olopezm]

Thanks again buddy,

I Just checked the Magnaflow site and found the replacement part for the GP is 99206HM.

Now I gotta make sure the shop has that same part number. Has a 2.5" inlet/outlet tho I'll see if I can find the PN for the high flow model .

Oscar.

[GTP Dad]

My GTP has TOG headers with a 3" down pipe, cold air intake, ram air hood and a 3.4" pulley on the supercharger, that is why I went with the high flow cat. For a NA engine you shouldn't need the high flow model a standard flow will work just fine and may save you a few dollars.

[olopezm]

Nice, Thanks again!

Now I just need to confirm the part number with the shop.

I really wish mine was a GTP but since I prefer the two door model and there aren't many GTP's like that... I stick with my GT and really love it!

Oscar.

[rickisrad]

you can make the GT very fast too. my past Gts were very fun. I am not sure what you can do in Mexico but, I put ER rockers, a CAI, 2.5 downpipe with high flow cat, zzp 1.0 pcm, shift kit all poly mounts, and front plog from ZZP. I was extremely happy with the performance. I did a little bit at a time due to the cost. Obviously I like the comp G better though

[olopezm]

Nice Rick, I wonder how many HP's you gained with all that stuff.

I would really like to get all that for mine but can't currently afford it until I find a stable job. Maybe then I'll ask for some advise to mod my car.

Oscar.

[rickisrad]

Its definately expensive... I did little at a time, and used my tax returns. I just liked how they drove street wise. as long as they were fast and fun, to me thats all that mattered. I did beat most of the others cars on the road though... especially when their governer kicked in.

[olopezm]

Hi guys, still haven't bought the cat for my car. I'm still at the price hunt...

I just wanted to ask you which brand would you prefer if Magnaflow or Walker. I've been taking a close look at guitarfish's post about his 2008 Prix and he seems to be a little unhappy about magnaflow's.

What are your opinions?

Thanks in advance,

Oscar.

[rickisrad]

Magnaflow will be fine for your car. They also have a better mettalic spun converter from magnaflow available. Guitarfish is having issues because the 08s are funny about the converter and o2 placement