Artemis Posted October 3, 2008 Report Share Posted October 3, 2008 Okay, so its been getting worse and worse... my car that is. Start it cold, it runs fine, gets a little warmer and its not as peepy as it used to be. Also, it doesn't seem to be as loud (dual magnaflows, LQ1) as it used to be. At stop lights and when I put it into park the rpms jump up and down and sometimes it dies. I just brought it to a mechanic next door and he turned it on and water came out, he says that the cat is probably fine then. But I'm not convinced. Also, i'm getting pretty terrible mileage lately I've got about 100 miles on this tank and its JUST above half. Im gonna get a second opinion, but could it be anything else? Quote Link to comment Share on other sites More sharing options...
jake91 Posted October 3, 2008 Report Share Posted October 3, 2008 im not a mechanic but normaly when the cat goes the car normaly gets louder and the cat should rattle Quote Link to comment Share on other sites More sharing options...
Leckenz34 Posted October 3, 2008 Report Share Posted October 3, 2008 Well if your worried about it, just get a new cat put in, or take it out all together, like me. 'cars loud as fuck and hauls ass. your problem could be related to 'engine sludge' I'd recommend some gasoline additive (some kind on injector cleaner then the next tank use some octane booster) and an oil additive (just a sludge remover or something along those lines, and go with a decent quality oil too, i use Mobil 1 Full synthetic extended performance 5w-30 in my 91 Z34, i find its a whole new car with that stuff in it but you can just use like a good Quaker state or better if you choose), I'd do an oil change to it right away if u haven't recently done so, and check the air filter that can sometimes be a cause Quote Link to comment Share on other sites More sharing options...
Fleeingpepper Posted October 4, 2008 Report Share Posted October 4, 2008 Seafoam it. Can't hurt anything. And if you think the cat might be bad then gut it and see if the problems are still there. Quote Link to comment Share on other sites More sharing options...
CSI_MuNkY Posted October 4, 2008 Report Share Posted October 4, 2008 With the RPMs doing that I would first take apart and clean the Aux post and all the wires on it. Mine does exactly that from time to time, all I do is pay a visit to the Aux post with a wire brush. The water is normal. The combustion process results in Carbon Monoxide and water as bi-products. Typically the water would turn into steam and evaporate, but in an exhaust system, some of it accumulates and comes out the tail pipe in liquid form... The baffles and/or perforated steel in cats and mufflers are a great place for this to occur. Hence why some mufflers appear to rust from the inside out. (I discussed this with my fiance to be sure I was right, she has her Bachelor of Science for Applied Chemical Physics, and is working on her Masters in the same field) Jamie Quote Link to comment Share on other sites More sharing options...
88red4cyl Posted October 4, 2008 Report Share Posted October 4, 2008 With the RPMs doing that I would first take apart and clean the Aux post and all the wires on it. Mine does exactly that from time to time, all I do is pay a visit to the Aux post with a wire brush. The water is normal. The combustion process results in Carbon Monoxide and water as bi-products. Typically the water would turn into steam and evaporate, but in an exhaust system, some of it accumulates and comes out the tail pipe in liquid form... The baffles and/or perforated steel in cats and mufflers are a great place for this to occur. Hence why some mufflers appear to rust from the inside out. (I discussed this with my fiance to be sure I was right, she has her Bachelor of Science for Applied Chemical Physics, and is working on her Masters in the same field) Jamie How would water coming out of the tailpipe mean that the cat is fine though? Quote Link to comment Share on other sites More sharing options...
CSI_MuNkY Posted October 4, 2008 Report Share Posted October 4, 2008 It wouldn't mean the Cats fine, it just means that the water has nothing to do with a bad cat... FWIW, I have had a bad cat with no rattle, and at the time I didn't realize it was loud as fuck because it was put on at the same time as 2 magnaflow mufflers, all were at least a couple years old I do believe. But when I swapped out the cat, the car definitely got quieter. Jamie Quote Link to comment Share on other sites More sharing options...
mfewtrail Posted October 4, 2008 Report Share Posted October 4, 2008 http://www.aa1car.com/library/converter.htm Quote Link to comment Share on other sites More sharing options...
Artemis Posted October 4, 2008 Author Report Share Posted October 4, 2008 Well, one detail I just remembered now, for the past few months, when I started the car cold and drove off it made a loud clicking noise until the car got warm. It has recently stopped doing that, originally I thought it was one of my mufflers going bad. I'll try to clean the AUX post, and seafoam it (bought 3 cans of seafoam recently it was on sale) I doubt its the air filter... just installed a CAI 4 months ago and the cone filter still looks great. Unfortunately having no cat at all is not an option... pretty strict about that in Ontario. Second paragraph in the cat article. "Driveability symptoms such as a drop in fuel economy, lack of high speed power, rough idle or stalling are classic symptoms of excessive backpressure due to a plugged converter. Checking exhaust backpressure and/or intake vacuum will tell you if there's a blockage" Quote Link to comment Share on other sites More sharing options...
CSI_MuNkY Posted October 4, 2008 Report Share Posted October 4, 2008 Unfortunately having no cat at all is not an option... pretty strict about that in Ontario. I have a friend that found a way to cheat that system. Her Cat is flanged on either end, when she goes in for her e-test she bolts up a good cat, any other time she has a cat that has been straight piped, so it still looks like she has a Cat on her car. The clicking is typical LQ1 behavior, I have never heard one that does not click on start up. Its the lifters, because all the oil drains down in the engine the longer it sits. I start my GTP about once a week and it will click for a good 20 minutes at idle every time. Jamie Quote Link to comment Share on other sites More sharing options...
93cutty Posted October 5, 2008 Report Share Posted October 5, 2008 When the cat in my bonnie went bad it sounded like rocks in a pop can when I started her. Quote Link to comment Share on other sites More sharing options...
BXX Posted October 5, 2008 Report Share Posted October 5, 2008 Its more than likely your cat. Mine is doing the same damn thing, and yes, I know mine is clogged... Summabitch will actually glow red after a bit of driving Quote Link to comment Share on other sites More sharing options...
w-bodys_are_the_best Posted October 5, 2008 Report Share Posted October 5, 2008 Bad Cat? Get a water bottle and spray them, they really hate that On my Z24 the cheap ass muffler that the previous owner had on there rotted out, so I replaced it with a piece of straight pipe and it wasn't really all that loud. Over the next year and a half, the cat began to get worse, it slowly over time got louder and started to rattle and stink like sulfur. It finally plugged one day about 50 miles from home, I could tell because it would get quiet like I had a muffler and lose power, but after stopping, or hitting a big bump it would gain the power back and at the exact same time would be alot louder. I took the pipe behind it off broke the few pieces apart that were in there, started it, and revved it to blow the pieces out. I repeated that process about 6 times using a tire iron to break the chunks into smaller pieces, threw the now messed up rear pipe back on and ran it like that almost all summer. The hollowed out cat acted like an echo chamber and made it ungodly loud, way too loud, so eventualy I replaced all the pipe with new, put a straight pipe in place of the cat, and a thrush glasspack in place of the muffler. It sounded pretty ricey at first for a 3.1, but it's been on there for almost a year now and sounds pretty good, we have no e-test around here, and it was alot cheaper that putting everything back to OEM. Quote Link to comment Share on other sites More sharing options...
55trucker Posted October 5, 2008 Report Share Posted October 5, 2008 If the Cat HAS melted down.....get under the car..(by that I mean...get the car off the ground) and with a hammer...rap the cat housing...if the substrate has solidified and broken into pieces you'll hear it rattling around in there...it can plug up the exit to the cat so to affect the exhaust flow and if the pieces are small enough they'll exit out the back and lay elsewhere in the pipes. Keep in mind that cats down fail just because they want to...usually something upstream has caused the failure. Quote Link to comment Share on other sites More sharing options...
GP1138 Posted October 5, 2008 Report Share Posted October 5, 2008 Keep in mind that cats down fail just because they want to...usually something upstream has caused the failure. x2... cats don't die, they are murdered. Quote Link to comment Share on other sites More sharing options...
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