P0430 Code After Doug Thorley Pipe Bomb Install

Just installed a Doug Thorley "Pipe Bomb" Y-pipe and my check engine light came on immediately. I checked it with a code reader and came up P0430, "Catalyst system efficiency below threshold". This makes sense because the Y-pipe deletes the two rear catalytic converters. I just cleared the code using the code reader but I'm curious if this has happened to anyone else and if they did anything differently to shut the check engine light off?

 

Assuming you still have the sensors in place, just no cats. Im guessing you will have to clear the code everytime the key cycles. Or get a simulator.

 

The code reader I have seems to have cleared it permanently

 

URD sells the 02 sim. I used it when I had longtube headers and competition y pipe. Keeps 02 monitor set to “ready” and check engine light off.

 

Both sets of O2 sensors are upstream of the rear cats, so removing them shouldn't make any difference. I've seen this called out as an advantage over the URD Y-pipes. You don't need a sim. The fact that it only threw the code once, immediately after installation, makes me think you might have just bumped or otherwise tweaked the O2 sensor during the removal and re-installation and that you should be fine now.

I'm planning to install one of these on my 2013 in the near future and would love to hear your overall impressions of it. I'm not sure if it's going to fit under my BudBuild skids or not, so anything you could tell me about clearance would be appreciated.

 

Yeah if you took out the cats then the light will come back on. You will either need to put new cats on or get the rear o2 sensor simulator.

 

Nope, not the rear cats. If you pull the fronts you need a sim, but the pipe-bomb leaves the fronts in place.

 

If you just got rid of the rear cars only, then you need to check for exhaust leaks. I had the same problem with a urd y-pipe. Once I fixed the leaks it went away. Most likely the leak is at the flange where it bolts to the front cats. It is easy for the seal to shift out of place.

 

According to Doug Thorley, the Pipe Bomb removes all catalysts. It does have two 10" resonators, but those aren't catalytic converters.

So yeah, you'll still need the O2 sims.

 

First 2 cats are part of the exhaust manifolds - you can't remove them by replacing the y-pipe. You'd have to remove the manifolds and install headers to replace the front cats. The pipe bomb only replaces the back 2 cats.

The second set of sensors is downstream of the first cats and upstream of the second cats - they measure the the output of the first set of cats. They're not measuring the output of the second set of cats which the pipe bomb replaces.

 

^This. The pipe bomb does not "remove all catalysts". No sims needed unless you remove the front cats, which as noted above are part of the exhaust manifolds. We are only talking about replacing the y-pipe here.

 

Here's a pic to give you an idea about clearance. Not sure how the BudBuilt skid plate mounts but this y-pipe does give quite a bit more ground clearance compared to the stock exhaust. It passes pretty closely to the four wheel drive actuator so I put a small heat shield over the pipe to protect that.

As for the check engine light it has remained on. This may be caused by the slight leak at the seam underneath the heat shield, (you can see the soot on the pipe in the pic), or it may be caused by the fact that the two rear cats were replaced with resonators. I'm going to tighten up the clamp at that seam to see if that fixes it and if not I'll buy the simulators.

For anyone curious about performance, I feel that this y-pipe did wake the truck up quite a bit. It seems to pull a lot harder in 2nd, 3rd, and 4th gear. Unfortunately I haven't done the numbers to see how it affected gas mileage. I still have the stock headers and the stock muffler and the truck has a slightly raspier sound to it, not really a lower rumble but not an obnoxious ricer sound either. I have about 1500 miles on it now and I'm pretty satisfied with it.

 

I think it will work with the skids without interference. I don't have a good picture, but they the rear plate is lower than the transfer case, and the BudBuilt rear crossbar angles down a couple of inches lower than the frame. I'm not a rock crawler, and only added skids to protect plastic and wires from branches and shit that might bounce up. They are also useful in floating over deep snow. Anyway, since I never plan to high-center the truck on a boulder I went with aluminum skids, and I will have no regrets if they have to be clearanced a bit.

As for the trouble code, I bet you have a leak where the PB connects to one or both manifolds. I saw in another post somewhere that the PB is set up for a thicker than stock crush gasket, and that if you use a stock one it can end up a little off-center (in the downward direction) resulting in a poor seal. Replacing the secondary cats with resonators wouldn't do anything, and I doubt a leak at the crossover would either. That said, the installation instructions say that the center clamp is not meant to be permanent, and is only there for fitment before welding the seam.

I am planning to have mine welded up at the local muffler shop after home installation. Once welded I am going to paint the crossover portion with some exhaust paint and then wrap it with heat-wrap. You are correct - we need to protect the transfer case actuator!

 

Hey paulk did you ever get those installed? I'm in Pittsburgh and wanting to do the exhaust manifolds on my V8 4runner and i am looking for someone to do that for me

 

Nope...had a custom system fabricated to retain all 4 cats.