Bad catalytic converter

[SI in GA]

Has anyone used the MagnaFlow 24177 replacement cat and what did you think about it. Running stock exhaust now.

[n8finn]

Funny you should ask. After a few mechanics told me I needed to replace my cat (for CEL PO420) I replaced it with this exact one. I'm still fighting the same code. More significantly, the difference in sound is what is irritating me the most. When I accelerate (generally after putting in 2nd) it sounds like there is an exhaust leak (hissing, higher pitched loud noises). It sounds fine when revving and not moving and the mechanic couldn't find any leaks.

I am also running stock exhaust BUT, after I saw how rusted the piping and flanges are, I decided to replace it with a Tanabe Touring Medallion...it's at the shop being installed as we speak, along with a new rear o2 sensor as the original seems to be acting strange from a volt test. At this point, I care less about my CEL since I'm inspected until next April....I just want it to not sound so shitty....so I'm asking the mechanic to triple check my exhaust manifold to make sure there aren't any leaks or that the new cat isn't vibrating against something....I will update you with what happens.

I keep hearing that aftermarket cats on our cars are a crap-shoot because of stringent emissions...makes me want to move back to Florida and put a fuggin test pipe on.

[SI in GA]

Thanks for the info, let me know what the outcome is. Funny thing I was looking at that same exhaust system, k series parts has it for 581 shipped. No emissions in ga. I was in cali for a while just left my Hawaii tags on while there to avoid problems.

[tommy]

I had 0420 as well, and just decided to replace the factory cat and the axle back exhaust at the same time - did Magnaflow for both. The shop also said that I needed to replace the downstream O2 sensor, which was done. Did that in October, and no CELs since. It is louder than stock obviously, but no weird sounds like n8 mentioned above. I've been happy with the setup since.

If you have no emissions in GA, you could always step up to a race header and kill the cat completely.

[n8finn]

Alright so tanabe exhaust and rear o2 sensor is installed. The CEL was reset and I haven't driven far enough yet to properly test but dang the tanabe touring medallion sounds SO nice. Deep, low-pitched and not obnoxiously loud....looks discreet as well, not stock but not over-the-top.... so pumped about that. The added noise does seem to drown out the weird sound at lower RPM from the magnaflow converter. I'm not sure if I should worry about it maybe I'm just being picky comparing it to stock. If the CEL stays off then great.... if not I'm reaching out to Magnaflow about maybe getting a replacement....I'll update this as I drive it more. Fingers crossed.

[n8finn]

So, I don't know if this would help you along, but Magnaflow offers two Direct-fit converters for our cars. The 24177's Grade is listed as "Standard" while the other 49142 model is listed as "OEM Grade" and is a little more expensive. I ordered the 24177 because I didn't realize this and the price was better.... I was on a performance shop's website catalog and saw these converters listed and that's where it had the specs. This may sway your decision and tommy, maybe you could let us know which MF cat you went with? Here's the comparison I found: http://store.rttuning.com/magnaflow/magnaflow-catalytic-converter-directfit/g-54038.aspx

[tommy]

I saw that yesterday when I went to MF's site yesterday before I wrote my response. Unfortunately, I can't remember which I bought or even what site I ordered it from. However, knowing me and my anal retentiveness, my guess is that I went with the 49142 due to the "OEM Grade" aspect of it and ate the additional cabbage that was required.
It's too bad that MF's pictures are exactly the same for both, and you really can't tell what would justify the price difference. However, I can't imagine that the differences are much. It's funny that the "OEM Grade" is listed as CA compliant in the "chart" view on MF's site, but says it's not CA compliant in the description when you view the 49142 itself. That needs to be cleaned up.

[n8finn]

So the converter I bought (24177) was the wrong one for me. Since a sticker under my hood *mentions* California, that means that my car is going to be picky about non-OEM Grade converters. If it doesn't say include California on the sticker then the 24177 will work. A Magnaflow rep confirmed the converter that I needed. The 49142 was what I SHOULD have went with. So, lesson learned I guess...I wonder if I could sell the 24177 and make a little of the money back, since returns are off the table....good information none-the-less!

[Hasbro]

Guardian hasn't been around for several years but I remember him stating he used a generic one that ran about $150.00 and it worked very well. It would require a search under his name, sorry, don't remember the details. Anything he suggested was based on expertise, he really knew his stuff.

I'll try to find the thread - I know I subscribed it.

edit; It was talonXracer, not Guardian. Haven't found it yet but here's a great thread from back when the really good motorheads were around;

http://www.ephatch.com/forum/showthread.php?45022-not-enough-back-pressure&highlight=catalytic+converter

I guess this will do for now, now I'm thinking it was Guardian;

http://www.ephatch.com/forum/showthread.php?43008-Hytech-Loop-Muffler&highlight=

[SI in GA]

Bad news gets worse, my clutch assembly went out, so my extra money went to that first. My exhaust will have to wait another month or so.

[SI in GA]

My wait continues, last month my radiator cracked. Just got it fixed yesterday, so many small problems happen lately.

[tommy]

They usually come in threes, so you should be good for a while. :happy:

[SI in GA]

Ok finally got the cat installed (MagnaFlow 24177). But two days before cat was installed the engine started running rough. I cracked #2 spark plug and melted the coil. Just bad luck. Now my passager headlight keeps blowing. Going to use silicon and test out wires.

Maybe one day I can afford that medallion

Oh car is running great yall

[SI in GA]

It's Saturday so we worked on the light. Seems the wire was loose on my depo headlamp. Electrical tape and gorilla tape should hold it for now. Going too try and get new connector.

Car is still running great no new codes.