Jeffery Starn Posted August 11, 2020 Share Posted August 11, 2020 Hey guys I have a 90 Comanche 4.0 4x4 and I want to change out my cat with HO cat, any recommendations on which is the best to install Link to comment Share on other sites More sharing options...
jdog Posted August 12, 2020 Share Posted August 12, 2020 check with your states regulations. do you mean a high performance cat? or a 90-92 factory cat? Link to comment Share on other sites More sharing options...
Jeffery Starn Posted August 12, 2020 Author Share Posted August 12, 2020 High performance cat Link to comment Share on other sites More sharing options...
Dzimm Posted August 12, 2020 Share Posted August 12, 2020 Do you have to pass a vehicle inspection? That will play a huge role in what you can get. As far as performance cats go, it's just got less material in it and thus less obstruction, they are usually called "high flow" cats. Many older vehicles in Iowa have no cat as they rusted out and were just replaced with pipe. We don't have inspections and unless you are being obnoxious and pissed off the cop to the point he is writing a ticket for everything he can find, I've never heard of anyone getting in trouble for it. I don't have a cat on any of my Jeeps just because they either didn't come with them or I didn't want to spend the extra money when rebuilding the exhaust. Your truck won't know the difference if you had a cat or not because there is no downstream O2 sensor in a 90 so it shouldn't really matter what you put on it. Link to comment Share on other sites More sharing options...
Eagle Posted August 12, 2020 Share Posted August 12, 2020 1 hour ago, Jeffery Starn said: High performance cat What makes you think the OEM cat isn't high performance? What do you think a non-OEM cat is going to gain you? Link to comment Share on other sites More sharing options...
Pete M Posted August 12, 2020 Share Posted August 12, 2020 If you're looking for more performance, the hands-down best bang for the buck is gearing. Link to comment Share on other sites More sharing options...
ghetdjc320 Posted August 12, 2020 Share Posted August 12, 2020 Please don’t take off your cat unless it needs to be replaced. All it does is stink up the cab and air around you and adds zero performance unless it was plugged (normally the ceramic honeycomb starts to come loose and blocks the flow). I run a magnaflow stainless cat that uses a stainless honeycomb vs the standard ceramic material. Here on island everyone removes there cat thinking they will gain power. Imagine walking down the road along the ocean with a nice salty breeze then a truck drives by and all you smell is gas for a minute. And for what??? Link to comment Share on other sites More sharing options...
Minuit Posted August 12, 2020 Share Posted August 12, 2020 Don't expect any performance improvement from replacing the cat unless the old one is plugged or broken. If it is clogged or broken, whatever common replacement is legal in your area will be fine. If the original flanges are still intact for the mounting, a direct-fit one will be easier to install than a universal one. Link to comment Share on other sites More sharing options...
Jeffery Starn Posted August 12, 2020 Author Share Posted August 12, 2020 3 hours ago, ghetdjc320 said: Please don’t take off your cat unless it needs to be replaced. All it does is stink up the cab and air around you and adds zero performance unless it was plugged (normally the ceramic honeycomb starts to come loose and blocks the flow). I run a magnaflow stainless cat that uses a stainless honeycomb vs the standard ceramic material. Here on island everyone removes there cat thinking they will gain power. Imagine walking down the road along the ocean with a nice salty breeze then a truck drives by and all you smell is gas for a minute. And for what??? I’m not removing the cat just replacing it my Jeep has 410000 miles on it and it seems like I’m getting restriction so I want to replace it Link to comment Share on other sites More sharing options...
88mancheman Posted August 12, 2020 Share Posted August 12, 2020 IMO the universal fit cats are the best bang for the buck, I’ve borrowed my neighbors flow master high flow setup for smog once & I didn’t notice any major seat of the pants improvement over the OEM setup and for the 400+ I just can’t see a reason todo so, I’m sure I’ll get some grief regardless but if your not in a smog county unbolt the cat from the headerpipe & drive around a bit, if you notice an improvement in performance your cat is prolly plugged up good, cats can also be gutted ;) you didn’t hear that from me though Link to comment Share on other sites More sharing options...
Jeffery Starn Posted August 12, 2020 Author Share Posted August 12, 2020 1 minute ago, 88mancheman said: IMO the universal fit cats are the best bang for the buck, I’ve borrowed my neighbors flow master high flow setup for smog once & I didn’t notice any major seat of the pants improvement over the OEM setup and for the 400+ I just can’t see a reason todo so, I’m sure I’ll get some grief regardless but if your not in a smog county unbolt the cat from the headerpipe & drive around a bit, if you notice an improvement in performance your cat is prolly plugged up good, cats can also be gutted ;) you didn’t hear that from me though Ha ya I live Cali and everywhere here is smog and BS so I need to keep a cat on, ive heard about gutting them but not sure if it will still pass smog with it like that Link to comment Share on other sites More sharing options...
fiatslug87 Posted August 12, 2020 Share Posted August 12, 2020 Holy crap the prices have increased! I purchased a Magnaflow CARB compliant direct-fit cat (I also live in California) a couple of years ago for ~$220, now they're north of $500!!! found a site for ~300 not sure if it's legit. https://jeepsarelife.com/magnaflow-exhaust-products-3391229-df-converter Link to comment Share on other sites More sharing options...
ghetdjc320 Posted August 12, 2020 Share Posted August 12, 2020 A regular magnaflow cat is under $100. Don’t gut your cat, it pointless. Just replace it with a weld on magnaflow if it is compliant. If not then get a replacement on rock auto. A gutted or removed cat is not an improvement over a good working unit. Just lookup how they work. They simple and effective devices. Essentially they are an afterburner for anything that didn’t get completely burned off in your engine. They aren’t a restriction or a filter. Here is a list of some: https://www.summitracing.com/dom/search/brand/magnaflow/part-type/catalytic-converters?SortBy=Default&SortOrder=Ascending They are available in both stainless and ceramic elements with or without heat shields (with is much better for our trucks) Link to comment Share on other sites More sharing options...
ghetdjc320 Posted August 12, 2020 Share Posted August 12, 2020 And these are all California EO complaint: https://www.summitracing.com/dom/search/brand/magnaflow/part-type/catalytic-converters/universal/yes/emissions/california-eo-approved?SortBy=Default&SortOrder=Ascending&N=%3A%2B Or rock auto sells them carb compliant oem one for $245 Link to comment Share on other sites More sharing options...
Jeffery Starn Posted August 13, 2020 Author Share Posted August 13, 2020 6 hours ago, fiatslug87 said: Holy crap the prices have increased! I purchased a Magnaflow CARB compliant direct-fit cat (I also live in California) a couple of years ago for ~$220, now they're north of $500!!! found a site for ~300 not sure if it's legit. https://jeepsarelife.com/magnaflow-exhaust-products-3391229-df-converter Awesome thank you I’ll check it out, did that one you got make a difference? Link to comment Share on other sites More sharing options...
fiatslug87 Posted August 13, 2020 Share Posted August 13, 2020 Not in performance, I needed a cat because I failed smog and I was also replacing my rusted muffler with a nice SS Magnaflow one so I purchased the matching cat. It did pass smog with flying colors. Link to comment Share on other sites More sharing options...
DesertRat1991 Posted August 13, 2020 Share Posted August 13, 2020 My truck gets emission tested annually. I installed this Walker CAT back in 2016. The truck passes testing just fine. https://www.amazon.com/dp/B000C945YQ/ref=cm_sw_r_cp_taa_2mwnFb77AF99X Link to comment Share on other sites More sharing options...
fiatslug87 Posted August 13, 2020 Share Posted August 13, 2020 2 hours ago, DesertRat1991 said: My truck gets emission tested annually. I installed this Walker CAT back in 2016. The truck passes testing just fine. https://www.amazon.com/dp/B000C945YQ/ref=cm_sw_r_cp_taa_2mwnFb77AF99X Not legal in California Link to comment Share on other sites More sharing options...
Eagle Posted August 13, 2020 Share Posted August 13, 2020 On 8/12/2020 at 3:22 PM, Jeffery Starn said: Ha ya I live Cali and everywhere here is smog and BS so I need to keep a cat on, ive heard about gutting them but not sure if it will still pass smog with it like that Best bet is that it won't ... Link to comment Share on other sites More sharing options...
jdog Posted August 14, 2020 Share Posted August 14, 2020 3 hours ago, Eagle said: Best bet is that it won't ... They won't in Colorado Link to comment Share on other sites More sharing options...
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