SOLVED: Another misfire chasing threads (2008 express van)

[Tonyv__]

You want the cat to show close to the same temp at front middle and back.

So driver side is reading like 350ish front/middle then over 500 at the back of the cat right where it welds into the exhaust pipe. I would think a blockage would be hotter in the front. But what do I know

Passenger side is a little more consistent like 400ish through the whole cat.

 

[Tonyrodz]

So driver side is reading like 350ish front/middle then over 500 at the back of the cat right where it welds into the exhaust pipe. I would think a blockage would be hotter in the front. But what do I know

Passenger side is a little more consistent like 400ish through the whole cat.

I'd say it's a little clogged. Hollow that beyotch.

 

[OR VietVet]

You have a problem with drivers side cat. If I was doing it, both would be replaced but is your call and unless sensors are relatively new, I would do all sensors, too.

 

[Tonyv__]

I'd say it's a little clogged. Hollow that beyotch.

That’s kind of what I’m thinking. I don’t have to pass emissions since I’m class 4A. I just don’t want my sensors to throw codes.

 

[Tonyv__]

You have a problem with drivers side cat. If I was doing it, both would be replaced but is your call and unless sensors are relatively new, I would do all sensors, too.

That’s the side I ran a misfire on for almost half a year before I figured it out. Maybe all that un burned fuel ruined it

 

[OR VietVet]

That’s the side I ran a misfire on for almost half a year before I figured it out. Maybe all that un burned fuel ruined it

That is what caused it. You repair it as you see fit.

 

[Tonyv__]

That is what caused it. You repair it as you see fit.

My tester is showing 8-11 psi back pressure at the 02 sensor closest to engine when revving engine. Definitely some restriction

It’s actually showing 0.06 - 0.08 MPA but that converts to 8-11 psi

 

[Tonyv__]

So I got around to “fixing” the exhaust. I intended on getting to both sides tonight but I was only able to attack the driver side. I’m about 4 1/2 hours into this project. The bolts on the exhaust flange were so rusty that of course I broke 2 and had to grind off the 3rd… getting the studs out of the manifold was another nightmare. Had to run to Home Depot and get the most expensive drill bits they had just to drill out the studs.

I will say though. She’s running like a r*ped ape now with no restrictions

 

[Tonyv__]

@Tonyrodz does your van sound a lot louder after you removed the cat?


I assumed it was a leak then I went under tonight finished the rear clamp and double checked everything. I got a throaty exhaust now lol. I don’t hate it but in a van it just sounds broken not so rowdy like a truck would

 

[Tonyrodz]

@Tonyrodz does your van sound a lot louder after you removed the cat?


I assumed it was a leak then I went under tonight finished the rear clamp and double checked everything. I got a throaty exhaust now lol. I don’t hate it but in a van it just sounds broken not so rowdy like a truck would

A little. Cats kind of act like mufflers. When I gutted the cat on my 01 it sounded really throaty, nice growl when you romped on it. Race van lol.