Exhaust refresh - DT shortys + Magnaflow cross pipe

[alia176]

Yesterday I did a project that might be some interest to you. I installed DT Shortys back in 2018 at 341,784 miles. IIRC, I installed the headers at home, then took the cats and the Magnaflow cross pipe and downtube to my favorite exhaust shop to finish up. Right now it's 2/11/25 at 426xxx miles.

For the last few months the CEL code kept popping up and going away and I've been hearing a rattling sound. I thought the Magnaflow pass cat at the header maybe lost the honeycomb pieces and that's what I was hearing. Couple of weeks ago I finally took the time to crawl under the thing and noticed that two hardware pieces came loose and part of the Y pipe on the pass side might have shifted. In another words, the pass header was not dumping straight into the pass side of the Y pipe (the pics will make sense). I'm not sure this leg slowly moved over or perhaps the exhaust shop made a booboo. In any case, it was time for a proper fix as I have all the tools for this job.

All new gaskets and hardware came from Toyota. Removing old exhaust hardware is a PITA as most of you know. I live in the SW and salt on the road is practically non existent but my hardware was corroded something fierce. With an impact gut and a die grinder, removing all of this junk was easy.

First I loosened the pass y pipe hardware and use the porta power spreader and heated up the correct part of the pipe with OxyAcet torch. Afterwards the flanged lined up and it was time to remove all hardware and clean up the connections. All of the connections accepted the toyota gaskets nicely except the one connection that I had to deal with. It doesn't have the nice recess for the oem gasket to live in so I had to slide it into place while the engine was running. This allowed me to figure out the optimum placement before tightening down the hardware.

Cont....

 

[alia176]

The rear most section after the 3rd cat, my oem hardware was too short so i'll have to rectify that. I'm using Magnaflow pipe connection to Gibson SS exhaust so the factory exhaust bolts with the springs weren't going to work here. The gasket here is the large one that leaves traces of itself after removal which you need to clean up before the new one goes on. Scraping off the large donut gasket required the usage of a chisel in places, on top of a wire brush. This is a very forgiving, soft gasket so i didn't need to all this but why not!

This is a little out of order, but I'm showing you the one place where the oem gasket is slid in. This is the pass side flange that had to be shifted over with the Portapower and heat. I probably could've used one those paper gaskets here, maybe even doubling them up wouldn't have hurt.

Anyway, hope this helps some of you visualize what a typical exhaust work on a non rusty V8 looks like. Let me know if I can answer any questions.

Oh, no more CELs and rattling sounds!!!

 

[LOSTR4]

That's a solid update! No codes like SUCH a validating success when working on these rigs! Nice works! Looks better than factory and I assume, performs better than OEM!!

Where'd you score/find the MF Cross-over pipe from?!

 

[alia176]

That's a solid update! No codes like SUCH a validating success when working on these rigs! Nice works! Looks better than factory and I assume, performs better than OEM!!

Where'd you score/find the MF Cross-over pipe from?!

I'm sorry bruh, I can't seem to find the receipt for the Cross pipe. I see that i bought the rear most cat from Planet Magnaflow, so that might be a start, maybe? I did the initial work back in 2018!!

 

[rdruss]

I have an '03 V8 4Runner and I shudder to think when I might have to do this because it's spent it's life in the rust belt and the nuts/bolts on the cross pipe no longer have hex heads of any sort, they look like rusted ant hills. I have a replacement 3rd cat from Magnaflow, had it for about 5 years, and most of the gaskets and nuts/bolts, just a project I can't get psyched for as it's not really needed yet.

 

[alia176]

I have an '03 V8 4Runner and I shudder to think when I might have to do this because it's spent it's life in the rust belt and the nuts/bolts on the cross pipe no longer have hex heads of any sort, they look like rusted ant hills. I have a replacement 3rd cat from Magnaflow, had it for about 5 years, and most of the gaskets and nuts/bolts, just a project I can't get psyched for as it's not really needed yet.

I feel ya. Exhaust work in the rust best is a $hitty job, no matter how you slice it. As long as you have all replacement pieces and hardware, you can go nuts with a sawszall! I used an angle pneumatic die grinder with a cutoff wheel to cut off two bolts that were corroded. I prefer a cutoff wheel over a sawzall due to the lack of space to maneuvering things.

 

[alia176]

Update:

The CEL returned with a P0430, cat below threshold so i bet I'm sucking in fresh air through the only connection that wasn't super solid. Damn it....

 

[BoneStockInTheory]

Update:

The CEL returned with a P0430, cat below threshold so i bet I'm sucking in fresh air through the only connection that wasn't super solid. Damn it....

Any update on solution to this? Have you gone in to rework the connection or have you just been living with the codes?
Curious as I'm getting intermittent 420 codes on my 06 V8 and am trying to find the best courses of action for the codes. I have a rattle sound and occasional foul smell so there is def a leak....