O2 sensors and cat elimination.
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The UPSTREAM are left connected close to the headers or even in the headers; those are required for the ECU to compute the air/fuel mixture when warm and cruising.
The DOWNSTREAM - some just zip tie them up to the wiring; others use a spark plug antifouler to move them out of the exhaust stream. Biggest thing is that they don't perfectly match the O2 swings of the upstream sensors; this tells the ECU that the cat's doing something.
They also sell O2 simulator circuits; but that's a bit overkill, it seems to me.
RwP
The DOWNSTREAM - some just zip tie them up to the wiring; others use a spark plug antifouler to move them out of the exhaust stream. Biggest thing is that they don't perfectly match the O2 swings of the upstream sensors; this tells the ECU that the cat's doing something.
They also sell O2 simulator circuits; but that's a bit overkill, it seems to me.
RwP
There are a bunch of companies that make O2 sensor plugs that move the sensor out of the exhaust stream just enough that it won't trip the check engine light. You just unscrew your downstream sensor(s), screw in the extension, and then put your O2 sensor(s) back into the end of the extension. Easy fix for running without cats.
On my 96 dakota and my 97 wrangler I pulled the cat when they started rattling and put in a pipe while I was going to order replacements. I never got a CEL so no new cat went in. I still have the dakota. O2s still in factory locations, and 50k miles (and counting 70 miles a day at a time) still no CEL.
Fast forward to my 01 Durango with a 360. I have had for going on 8 years. That damn thing, had a inefficient catalyst code that drove me nuts that I was able to stave off for a while with an old spark plug non fouler between the sensor and the bung but shortly before the original engine had to be replaced (at 258k) I had to replace the damn thing. I'd replaced O2s a couple of times prior to that.
I had had an injector stick wide open on the replacement engine which killed it in short order. And melted down that brand new cat. Replacement engine number 1 (a complete and total rebuild included all necessary machine work) lasted all of 3 hours and less than 6 miles, and it killed that new cat. While I waited for my son and tow strap I watched the cat glow BRIGHT cherry red.
So when I got around to putting engine#2 in (a CL buy with about half of the miles that the durango has on the body, all regasketed with the brand new EQ heads that Id had on replacement engine#1) I put a pipe in in place of the cat with (again) a new round of O2s. That SOB went all of 162 miles before the CEL came on due to inefficient catalyst. So I had no choice but to buy another one. Was none too happy about that. So far 15k miles since engine#2 and cat #2 went in and so far so good...
I treat cat converters like an uninvited house guest.as long as they cause no issue I leave them alone. As soon as I have a problem out they go.
Fast forward to my 01 Durango with a 360. I have had for going on 8 years. That damn thing, had a inefficient catalyst code that drove me nuts that I was able to stave off for a while with an old spark plug non fouler between the sensor and the bung but shortly before the original engine had to be replaced (at 258k) I had to replace the damn thing. I'd replaced O2s a couple of times prior to that.
I had had an injector stick wide open on the replacement engine which killed it in short order. And melted down that brand new cat. Replacement engine number 1 (a complete and total rebuild included all necessary machine work) lasted all of 3 hours and less than 6 miles, and it killed that new cat. While I waited for my son and tow strap I watched the cat glow BRIGHT cherry red.
So when I got around to putting engine#2 in (a CL buy with about half of the miles that the durango has on the body, all regasketed with the brand new EQ heads that Id had on replacement engine#1) I put a pipe in in place of the cat with (again) a new round of O2s. That SOB went all of 162 miles before the CEL came on due to inefficient catalyst. So I had no choice but to buy another one. Was none too happy about that. So far 15k miles since engine#2 and cat #2 went in and so far so good...
I treat cat converters like an uninvited house guest.as long as they cause no issue I leave them alone. As soon as I have a problem out they go.
Thanks ! I really appreciate the info
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