silverton Posted August 27, 2011 Share Posted August 27, 2011 my 95 SE had a precat. the non-precat trucks have a pipe there that is a bolt in replacement, which I did. it changed the exhaust note far more than replacing the muffler with a pipe did! Also, a precat is not going to change your emissions test result unless you do the test on a cold start. Also, I would like to take a guess that the trucks that have carpet fires on the driver side of the truck, are equipped with a precat, I was seeing temperatures of 800-off the scale of the pyrometer at the inlet of the precat. Link to comment Share on other sites More sharing options...
Trogdor636 Posted August 27, 2011 Share Posted August 27, 2011 (edited) Mine is originally from the Chicago area. No precat, still has the stock muffler Edited August 28, 2011 by Trogdor636 Link to comment Share on other sites More sharing options...
Precise1 Posted August 27, 2011 Author Share Posted August 27, 2011 he's showing the signs, lets put him down before it gets worse! Bring friends, it isn't going to be easy... my 95 SE had a precat. the non-precat trucks have a pipe there that is a bolt in replacement, which I did. it changed the exhaust note far more than replacing the muffler with a pipe did! Also, a precat is not going to change your emissions test result unless you do the test on a cold start. Also, I would like to take a guess that the trucks that have carpet fires on the driver side of the truck, are equipped with a precat, I was seeing temperatures of 800-off the scale of the pyrometer at the inlet of the precat. Interesting correlation, but I wonder if your pre-cat was clogged?? B Link to comment Share on other sites More sharing options...
adamzan Posted August 28, 2011 Share Posted August 28, 2011 Ok so I have had mine emissions tested since having the pre cat /cat removed and since I have the papers from both tests here I found that it tested better with the precat (i figured as much) than with the walker aftermarket that is on there now. As long as it passes and I get my sticker I don't' give a @!*%. Link to comment Share on other sites More sharing options...
Slashjt Posted August 28, 2011 Share Posted August 28, 2011 Mine had a Pre-cat, I took that one out, along with the cat. Replaced that with only 1 Magnaflow Cat, ever test went O.K. Felt more powerful and live. Link to comment Share on other sites More sharing options...
lint Posted August 28, 2011 Share Posted August 28, 2011 (edited) Also, I would like to take a guess that the trucks that have carpet fires on the driver side of the truck, are equipped with a precat, I was seeing temperatures of 800-off the scale of the pyrometer at the inlet of the precat. Yes, I'm inclined to agree here. My floor was burned through & I have a pre-cat. I notice that there is no heat-shield attached to the body for the pre-cat, like there is for the cat. Edit: Now I'm losing it!! There IS a heat shield for the pre-cat, just not continuing forward enough to cover the flange! Edited August 28, 2011 by lint Link to comment Share on other sites More sharing options...
sewebster Posted August 28, 2011 Share Posted August 28, 2011 My floor was rusted through and I have no pre-cat. Link to comment Share on other sites More sharing options...
silverton Posted August 29, 2011 Share Posted August 29, 2011 Interesting correlation, but I wonder if your pre-cat was clogged?? B Nope, both my cats were in good condition. Light comes through on the pre-cat with no material falling out or deformed looking. Link to comment Share on other sites More sharing options...
Precise1 Posted August 30, 2011 Author Share Posted August 30, 2011 Yes, I'm inclined to agree here. My floor was burned through & I have a pre-cat. I notice that there is no heat-shield attached to the body for the pre-cat, like there is for the cat. Edit: Now I'm losing it!! There IS a heat shield for the pre-cat, just not continuing forward enough to cover the flange! Both my precats have heat shields and actually, most of the piping is shielded quite well also. My experience is that it is the leaking flange that lights up and burns through the floorboard. Nope, both my cats were in good condition. Light comes through on the pre-cat with no material falling out or deformed looking. The only other heat generator I could think of other than a leak... B Link to comment Share on other sites More sharing options...
Precise1 Posted August 30, 2011 Author Share Posted August 30, 2011 Precise, do you recall the model & price of that Magnaflow? It was a 2" diameter, correct? No, not exactly, but it shouldn't be hard for me to look up so let me get back to you. Yes, it was a 2" Magnaflow high flow cat, going larger wasn't legal in Ca, 2" was the max and probably sufficient anyway. B I'm almost certain that this is the one I got, Magnaflow #39760... http://www.truckpartshub.com/product/magnaflow-39760-direct-fit-converter I haven't found any paperwork proving it yet, but I seem to recall that part number and there are only 2 models legal in Cali, the universal and the direct fit one I listed. I think the site bought it from is on my work emails so I'll try looking tomorrow. IIRC it was about $120 to my door so the link I listed isn't a bad price... B Link to comment Share on other sites More sharing options...
silverton Posted August 30, 2011 Share Posted August 30, 2011 The only other heat generator I could think of other than a leak... B Only leaks in my exhaust is at the manifolds like 90% of the Pathys out there, and where the clamps are that are holding on the pipe that replaced my muffler. I was amazed and frightened by the temps I saw. Link to comment Share on other sites More sharing options...
Precise1 Posted August 31, 2011 Author Share Posted August 31, 2011 No sheit, you'd see it if it was dark!! That can't be normal. It would probably run real clean though... B Link to comment Share on other sites More sharing options...
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