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[ScotchStapleton]

I have had my 2003 EB for a few years now but am new to the forum.

For the better part of a year now I have had some power issues with my Expy. It seemed to lag hard when attempting to pass people WOT. I recently (4 months) moved to a new city and now a very long grade has become part of my daily commute. More and more I have been feeling the power loss when climbing hills. I have looked through some of the threads on here and found that my symptoms seem to point to clogged catalytic converters. The clincher was when one of my DPFE lines started blowing off regularly. I have ordered direct-fit replacement Magnaflow cats as I was able to get a pretty good deal on them, and this allows me to swap them myself.

Now for the problem, the driver side is on backorder until January 15. I have checked every retailer in my area and most of the online retailers but everyone seems to ship direct from Magnaflow so there is no inventory. The truck is nearly undriveable in it's current state, but I rely on it for transporting the family. What I would like to do is remove the cats and run open for a couple of weeks until the new ones arrive. Aside from the obvious change in noise and smell, are there any serious risks to running this way?

 

[R4mbo]

Hi, if i were you i would empty the old cats until the new ones gets shipped.
You can use a drill to empty them, it will throw a check engine light, because the o2 sensors will see that the cats are bad.

 

[1955moose]

Why don't you remove the rear cats for now. Everything other readers write in they should run just fine without them. Dumb question? Did you or someone diagnose that your problem is cats? You can use a handheld temperature guage to measure temp, against all four cats when warm. If clogged you will have a higher temp at exit of cat, much higher because heat is trapped. They also make a screw in guage that goes into o2 sensor port, to read pressure. Just my 2 cents. Keep us posted if removal brings power back,


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[ScotchStapleton]

Hi, if i were you i would empty the old cats until the new ones gets shipped.
You can use a drill to empty them, it will throw a check engine light, because the o2 sensors will see that the cats are bad.

That was an option I had considered but it seems that if I can just run without any pipe attached it would save me the work of hollowing out the existing cats. Plus if I leave the clogged cats intact I can recycle them and make some money back.

 

[ScotchStapleton]

Why don't you remove the rear cats for now. Everything other readers write in they should run just fine without them. Dumb question? Did you or someone diagnose that your problem is cats? You can use a handheld temperature guage to measure temp, against all four cats when warm. If clogged you will have a higher temp at exit of cat, much higher because heat is trapped. They also make a screw in guage that goes into o2 sensor port, to read pressure. Just my 2 cents. Keep us posted if removal brings power back,


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My understanding was that the exit temperature would actually be lower when clogged. I am seeing ~700F at the inlet and around 330F at the exit. This was my first indicator. In an effort to relieve some of the backpressure I removed the 02 sensors that are between the first and second cats. There was almost zero change. Then the DPFE line started blowing off from the driver side manifold. This tells me that likely all four cats are clogged. Removing just the rear set seems like it would gain me nothing in this scenario.

 

[1955moose]

My bad, your right on the temp thing. The only reason I recomended rear cats is that it shouldn't mess with the computer trying to compensate. You could get some straight pipe and bypass, what you got to lose, he'll it might run great. These original cats must be like other items on these expy's, not of the best longevity. My truck is only 1 year since I bought, and I've changed or have to change more items. I've owned over 20 cars/trucks in my 44 years of driving. This one goes through parts at an alarming rate. You've got 3 weeks till cats come in, what the hell get some connecter pipes and hook it up!


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[ScotchStapleton]

My bad, your right on the temp thing. The only reason I recomended rear cats is that it shouldn't mess with the computer trying to compensate. You could get some straight pipe and bypass, what you got to lose, he'll it might run great. These original cats must be like other items on these expy's, not of the best longevity. My truck is only 1 year since I bought, and I've changed or have to change more items. I've owned over 20 cars/trucks in my 44 years of driving. This one goes through parts at an alarming rate. You've got 3 weeks till cats come in, what the hell get some connecter pipes and hook it up!


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Well, removing the cats was a little more of a hassle than previously hoped but they are now gone. That was definitely the problem! My Expy feels like it runs better than the day I bought it. Possible the cats were slightly plugged even then I guess. And it sounds when I get the throttle down. I may have to get some test pipe in just so I don't get in trouble with local law enforcement.

 

[1955moose]

Ah that's so cool, glad to hear it worked. Wish I could eliminate mine. Here in the Bay Area, you don't dare. Every year their adding more and more. Wonder if hybrids fail smog. These expeditions seem to be famous for clogging cats. Seems that and bad coils are 80 percent of the posts.


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