george16

I felt that I lost a lot of low end torque. It's a custom 2 1/4" piping with a stainless Magnaflow muffler installed. Sound is good but like I said I definitely lost a lot of low end torque. Time for the SC i think . Anybody noticed this too? I'll post a pic later.

George

4RUNR

Toyota tunes engines. Meineke welds.

Birdman

You may just need to give the ECU time to adjust, although I'm not sure how it would compensate for this. I took out the fuse for the ECU to speed things up just in case. Does anybody know if this type of mod will result in the ECU making any changes to the mix?

Good Times

Birdman is definitely on the right track. Whenever you do any performance mods it's a good idea to clear the ECU so that it can relearn w/ the new settings. Give that a try and see if it works. Best to pull the fuse and let it sit for a few minutes.

Good Luck

george16

Thanks guys. I did that this afternoon. I haven't driven it yet since pulling out the EFI fuse so hopefully it'll work out ok. I let you all know the outcome.

George

grams72

ECU not EFI

grams72

Do you still have the Cat. installed?

AgRunner06

I'm almost 100% positive that the 3.4 is supposed to have 2.5" piping not 2 1/4". I've got 2 1/4" pipe for my exhaust. If that is really what you used then I would say that is why you lost power. You increased the backpressure thus losing power.

george16

The pipe size for the 3.4 is 2.25". It's not 2.5" as a lot of people think. I did the measurements and have the shop verify it to be 2.25". I actually lost backpressure hence the lost low-end torque.

George

george16

Yes I do. The stock cat is still installed.

George

george16

Good thing I didn't have Meineke do the exhaust .

George

AgRunner06

george16

That info sheet lists the recommended pipe sizes for different type of engines. Unless you have a 3rd generation runner, you will know exactly what the OEM exhaust pipe size is. Go to the dealer with your tape measure and measure it for yourself . I decided have to stay with the OEM size hence I had a 2.25" catback made . The 3.4 only makes about 183 HP at the crank.

George