Dead catalytic converter, vast improvement....

I don't post all that often, but I'd like to offer my experience in the hope that someone else may benefit.

2002 standard cab, 4x4 with a 2.7 and 5 speed. I bought it late last year with 175K miles. New frame and a PO who had taken good care of the running gear.

I bought it in FL and drove it to SC where I hooked up to a UHaul trailer and pulled it back to Maine. I drove all the way in 4th gear as 5th with the 225 70 16 tires were too much for the engine, or so I thought.

When I got to Maine, the P0420 code suggested a failing cat, but I assumed it was the later life of the engine. I put an Underdog Racing Development black box into the line from the #2 ox sensor. That cured the code, but the engine performance was still anemic. The change to 225 75 15 snow tires seemed to help and I assumed that the PO had simply put tires that were too large on the truck.

Now I owned a 97 4Runner when I was overseas and the performance of the 2.7 was, if not spirited, very adequate. Unlike this truck.

Then my muffler split and it quickly became obvious that the motor was having a hard time breathing as little was coming out the pipe and lots out the split.

A couple of days ago, I took it to my local guy who "dealt" with the disintegrating cat and installed the new muffler that I'd ordered from Rock Auto.

What a difference! The truck behaves like it has a new engine. Pickup (pardon the pun) and power through all gears is remarkable compared to before. Even with the larger rims and tires re-installed, performance is excellent.

Examination of the old exhaust system revealed that the failing cat had released chunks into the muffler and that the exhaust flow was severely restricted. I consider myself fortunate that I did not burn a valve!

What can I say? I'm very pleased to have my truck running right and I hope that this little story is of use to someone out there.

 

Good news! Are you really running 225s? That's a really small tire.

 

The 225 75 15 was the recommended tire on the standard cab 4 cyl (I think). The profile, according to the tire computer I found, is about 10% smaller than the 265 70 16 tires. The larger tires and rims actually came off a 4Runner and the PO bought them because he thought they looked cool. And in fact they do look pretty good....

 

Actually, I'd like to make a correction. The drive up from FL was done with 265 70 16 tires. I installed the 225 75 15 snow tires once I got to ME.

 

actually all 4x4 came with 31x10.5x15 (98-00) or 265/70-16 (01-04) tires. due to the gearing of 4.10:1 (v6) or 4.38:1 (i4).

those tires will need a speedo correct and will ultimately kill your gas mileage

the 225/75-15 were on 95-97 Tacomas. THe PO probably picked up a set of 4Runner rims cause his came with the steelies.

 

Which cat did you get?

 

I didn't buy a cat, it's still the original, but with the insides..... um...... modified.

 

So you kept the Underdog Racing Development black box connected?

 

This website indicates all the tire options for my year truck. I'm pretty sure it came with 225 75 15s.

OEM Tacoma Tire Sizes
Model Year Original Factory Tacoma Tire Sizes Sorted By Rim Size
1995-2000 195/75 R14 215/70 R14 225/75 R15 31×10.5 R15 265/70 R16
2001-2004 205/75 R15 225/75 R15 235/55 R16 265/70 R16 –
2005-2014 215/70 R15 245/75 R16 265/70 R16 265/65 R17 255/45 R18

Oh and yes, I kept the URD black box installed.

 

I have no clue why Toyota even put a sticker on the door with that tire size. main thing to do is check your gear code.

http://www.off-road.com/trucks-4x4/tech/toyota-differential-identification-18588.html (have to read down the page a bit)