hey everyone!

About a month ago I bought my second 4Runner. She’s a 2004 V8 SR5. I live in Texas and the protocol is that when you buy a vehicle the dealer will have it inspected prior to purchase. So I bought the car, whatever. A week ago I noticed a burning smell whenever I went up particularly bigger hills (I live in the hill country so this is kinda problematic), so I decided I needed to take it into a mechanic ASAP. I looked up the problem on some forums and i narrowed it down to transmission fluid or exhaust build up. The technician called me today and told me it was exhaust build up from my catalytic converter failing. He quoted me $2650 for labor and parts. I know I can’t replace the part myself, but this price seems a little out of a reasonable range for a catalytic converter considering the OEM part is about $750. I guess I’m just wondering if I should call around and ask other technicians for quotes because I feel like I’ll be getting robbed in a way.

It took me about 2 hours per side to change with a second person also a possibility of stripped bolts and breaking studs... so if pricing includes all the rusted headaches than worth it.

The cats are made/welded onto the exhaust manifolds, which are a real pain to remove and replace on the V8, labor intensive.

You can't just buy OEM cats without the exhaust manifolds and just replace the cats.

Before you get too deep into repair/replacement, is it a sulfury smell when you get on the gas?

Search the forums here, that seems to just be a feature of the cats used in the 4th gen, regardless of engine. Many people reported it when these trucks were new, and many people are still noticing it years down the line.

Yes kind of. But it only happens when I go up this one hill near my house that probably has a 250-300’ change in elevation. I try to be gentle when accelerating and get decent gas mileage (usually around 21 mpg). I read somewhere that a “bad” catalytic converter can decrease fuel efficiency which I have noticed a bit. I want to drive it to my trusted car tech, but he’s over 200 miles away and I’m not sure my car will make it there safely.

Did they say how many CC's they would be replacing? There's multiple on these vehicles. One on each side welded to the exhaust manifold and one before the muffler I think but not sure on the V8. How did they decide there was an issue?

I’m not sure yet. I’m picking it up after work today. I’ll post their diagnostic when I have it.

Okay, so here is what they gave me. Not really definitive so I’m not sure how to move forward.

I don't know what's going on with your truck but 21 MPG in a V8? That must be on the descending side of the hill. ;-)

A smell like burning rubber sounds more like brakes than catalyst, to me. A mad afternoon on the motorbike results in similar . In your case I wonder if it's a slightly sticking caliper.

Those prices don't seem out of line to me for a Toyota dealer, the labor seem reasonable considering what they have to do to replace the manifolds/cats assemblies.

That being said, if it were me I wouldn't replace them until I started getting codes that warrant them needing replacing, especially since it says "burning rubber smell" which I have never seen nor heard of a bad cat causing such a smell.

lol no. I’ve improved my efficiency over the years. I also don’t like to spend money on gas so that was another incentive to learn how drive efficiently. I average 20.8 mpg and commute about 30 miles a day so I experience both city and highway.

Maybe a bad/dry wheel bearing too? Agree I would want to check all the stuff I can check for free myself before throwing money at new cats.

OP, if you pull over without braking (just let the truck roll to a stop) you can CAREFULLY feel each brake disc to see if one is significantly hotter. Or use an IR thermometer maybe.

Gahdamn!! Im getting like 12-13mpgs maybe 14-15 all highway. Is yours 2wd? stock tire size? would love to know, very frustrated with my mileage and I definitely don't have a "heavy foot" lol.

I possibly agree on this one I had a seized rear caliper and messed with driving and could smell it. Put a hand on all your wheels right after driving on the highway if any one is more hot than the others possibly a caliper issue. 4th gen rear calipers are notorious for seizing, I replaced mine with 5 gen calipers...

5th Gen 4Runner Brakes Upgrade (for 4th Gen 4Runner)

oop sorry @SurferUK already said this "Maybe a bad/dry wheel bearing too? Agree I would want to check all the stuff I can check for free myself before throwing money at new cats.

OP, if you pull over without braking (just let the truck roll to a stop) you can CAREFULLY feel each brake disc to see if one is significantly hotter. Or use an IR thermometer maybe."