Catalytic converter started blowing chunks yesterday after truck would not start and someone decided that pouring fuel down the throttle body was helping. When the problem turned out to be a bad coil which was replaced the truck started but would not run without accelerator assistance. It began to smoke and backfired a couple of times before sounding like it was blowing nuts and bolts through the exhaust. Shut it down and found that the nuts and bolts noise was actually pebble sized chunks of the stuff that is inside the Cat. One chunk was almost an inch in diameter and was about 40 feet away. So I know that I will be replacing the Cat and probably the muffler but because I shut the thing down I'm not sure why it was running so sluggish and smoking before it blew chunks. So I am wondering if I can start it while I have the exhaust unhooked from the crossover pipe back to determine if there is a bigger problem that needs to be addressed.
No just for diagnostics purposes you can do that. My friends ran his FI bronco for a while after we cut the exhaust off before the converter. No harm done
No just for diagnostics purposes you can do that. My friends ran his FI bronco for a while after we cut the exhaust off before the converter. No harm done
Just don't leave it undone and ride around for an extended period like that. Besides the cops possibly getting after you, people "say" you will burn up valves without full length exhaust.. IF that is true or not......?? good luck with your diagnosis.
Also if this helps or not... My friends converter was rattling horribly, i guess just aged, so we took it off and punched the catalyst out so now there is just a converter shell there. 1998 jeep cherokee 4.0l. Check engine light comes on occasionally but hasn't since we replaced o2 sensors.
Just don't leave it undone and ride around for an extended period like that. Besides the cops possibly getting after you, people "say" you will burn up valves without full length exhaust.. IF that is true or not......?? good luck with your diagnosis.
Pretty much an old wives tale, look at all the race cars with open headers and exhaust. Used to be people sweated valves warping from cool air reaching the valves, good theory, but not going to happen.
Also if this helps or not... My friends converter was rattling horribly, i guess just aged, so we took it off and punched the catalyst out so now there is just a converter shell there. 1998 jeep cherokee 4.0l. Check engine light comes on occasionally but hasn't since we replaced o2 sensors.
How does it sound without running through the Cat. Is it obnoxious loud or just annoying loud? Annoying loud I have to get used to, obnoxious loud the neighbors have to get used to. Neither one meets California smog requirements though, right? But if it'll get me bye for awhile I'd be willing to run it like this, for awhile.
The jeep isn't all that loud and we also replaced the muffler with a glass pack. If you were to gut the converter and bolt it back up with the stock muffler, it would not even be annoying, no where near obnoxious
If you don't have any O2 sensors after the cat, it won't cause any problem if the converter is missing.
If you do have an after-cat sensor you need to replace it with something like this http://www.afterthoughtsauto.com/o2sim.html so that you don't get engine computer errors.
The jeep i was talking about has before and after o2 sensors and we haven't had a problem. It kept on working fine, other than tripping the check engine light occasionally
No after Cat 02 sensors to worry about but I do have those pesky California emissions tests to pass. Actually, to hell with them and their strict *** rules. I don't need no stinkin tags man. I see vehicles on the road everyday that don't have current tags, and in this economy they got alot of nerve expecting me to pay smog and registration fees when their already jackin me every time I put gas in the tank. Lower the price of gas and I'll pay my registration and get my **** smogged. Otherwise they can go piss up a rope.
Well then i'd say if your converter is **** anyways, gut it out and put your system back together. Enjoy the new sound of your truck and piss on the "rules"!
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