15 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
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Discussion summary
YOUR RESEARCHGood solution for non-CEL cats?
Leading reported evidence
Install top gear cats a couple of years ago
Performed · outcome unconfirmed
No successful repair reported for this finding.
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Performed · outcome unconfirmed
I also installed Top gear cats a couple of years ago.
Leading evidence: 'Install top gear cats a couple of years ago' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Install top gear cats a couple of years ago' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.
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Performed · outcome unconfirmed
I ran their 200 cell cats for a year or two and after a spirited driving session they literally fell apart inside.
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Performed · outcome unconfirmed
I used 45deg spacers on the downstream O2, which worked, and I have run without a CEL since then.
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15 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.
Rennlist: 1 discussions
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My OE cats failed about 3 or 4 years ago. Bricks inside became loose and were rattling around, rubbing against O2 sensors, etc. Fail.
To save money, add power, and add noise, I replaced them with Topgear 200 cell sport cats, for a very low price, which claim to not cause a CEL. Spoiler alert: They definitely cause a CEL. The company won't return my calls or emails about it. I wouldn't buy from them again. IF I run the car really hard at the track the light might stay off for a while, but in normal around-town driving it'll come back in 100 miles or so. Looking for options to keep the light off, as I'm sick of looking at it and turning it off periodically, and wondering if it will pop on at annual state inspection time and cause me to fail.
- Has anybody successfully used O2 sensor spacers on the downstream sensors to keep the light off? I see a lot of posts speculating about it, but no posts saying definitively "this particular setup/spacer works". I've got some 90-degree adapters coming in the mail to try out, because they cost basically nothing and take only minutes to install, but I have my doubts that they'll reliably keep the light off.
- People talk about getting a RoW tune to effectively turn off the downstream O2 sensors. Who can do this, and how much $$ am I looking at? I'm in central PA. Is this a things where I need to take the car to somebody, or do I mail them my ECU?
- If there's a reasonable source for replacement OE-style cats, I'd be interested, as I'm not in love with the noise from the Topgear cats. They're sweet on the track, but kind of obnoxious around town. I have Milltek mufflers so the exhaust is already louder than stock, and with the sport cats it's a bit much. BUT, everything I can find is like $3k or more for both cats, or they are out of stock. Anybody got good tips?
Thanks!
Same issue with the Top Gear cats. These worked for me:
https://www.racdyn-usa.com/PROD/130+10+10+014.html
Fit up 90 deg ones first both those put the O2 sensor wiring right on the piping. Much better fit with the 45s.
Been running 200 cell FVD cats and using 02 sensor spacers since 2007. They definitely work. Never had a cell problem except for when the O2 sensor needed to be replaced. Had nothing to do with the spacer.
I put one of those mini-cats in my 06 Cayman S, was throwing Cat codes every time. Put it in the O2 sensor "EDIT AFTER" the cat on Bank 1 (passenger side on a Cayman). I've put about 250 miles on it since and no more codes!
Top Gear is absolute trash. I ran their 200 cell cats for a year or two and after a spirited driving session they literally fell apart inside. They came up with every excuse why their cats didn't fail, but it was obvious the internals were trash.
Currently I ditched cats all together and am running a non-catted x-pipe and believe it or not I am yet to throw a check engine light. While the Top Gear ones threw lights more than occasionally.
Even had the car sniffed for emissions and it passed fine which surprised me.
Hopefully I can make another few years without having to deal with emissions. My state will opt-out my car after it is considered an antique after it is "25" years old.
I ran these, they worked cat-less.
https://www.maxspeed-motorsports.com...s_Porsche.html
***The factory cat pipe had the catalyst element surgically removed and re-sealed up, selling the elements paid for the welding work and the mini-cat's)***
The aftermarket cat on my ‘90 just died (rattling) after 6 years and maybe 30,000 miles. This is totally unacceptable as I’d been getting 80-100 miles out of the factory cats. However the Mazda cat is pretty pricy these days so I went with an el-cheepo replacement back in 2008. Obviously I made a bad choice that time so I am hoping to come up with a better but still affordable solution. Any suggestions? Performance is not the main issue except that it needs to last longer.
I also installed Top gear cats a couple of years ago. They also caused CEL despite the advertising. I used 45deg spacers on the downstream O2, which worked, and I have run without a CEL since then. 45deg is a little trickier to find, but they fit best with the space and O2 wire length restrictions.
Top gear was also completely radio silent when I tried to contact them after installation.
I've posted this result a couple of times in relevant threads around the forum, but I feel bad that the OP didn't see that before purchasing.
BTW, the factory CATs will pretty much last substantially longer than any aftermarket CATs. The factory have a tighter mesh, with thicker heavy metal layers. Going with high flow 200cell (or less) has a downside. Even if they don't cause a CEL, they won't last as long.
I don't have information on for your Mazda, but generally "el-cheepo replacements" have a downside. If it lasted 2.6x less miles (80/30), then hopefully it was 2.6x cheeper?
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