Exhaust cutout and ECM learning curve?

ex-chevyguy · #1 (**permalink**) 04-03-2008, 06:47 PM

I know there was already a thread about exhaust cutouts but it didn't cover something that I just thought about. I have desided that there is no one exhaust that is going to make me happy so I have been looking into exhaust cutouts and it has brought up a new question. With all the "learning" that this truck is always doing; changing a/f ratio, valve timing, shift points, ect, what kind of effect would changing exhaust back-pressure back and forth from stock to strait pipe have on the motor? I want to put an electric cutout in front of the stock muffler and run 3" strait pipe off of it with it exiting behind the drivers side rear tire, so it looks like a dual system from the rear. So if I go with this plan, will there be any ill effects from switching back and forth on a regular basis? Will the truck constantly be trying to change its' settings for the back-pressure of each system and run porely? Thanks for any insite!

Negra · #2 (**permalink**) 04-03-2008, 08:32 PM

These motors learn much faster then people are led to believe.(forum groupies)
They DO NOT take HUNDREDS of miles

Just vary the driving from WOT to Cruz and back to WOT.
Pinging the rev limiter in acouple different gears etc.The ECM will pick up the driving habits very quickly and make all the adjustments in well under 50 miles.

Running a dump will result in inconsistent performance as it will have to relearn back and forth between open and closed.

Best of Luck !

thumbster · #3 (**permalink**) 04-03-2008, 09:14 PM

When we used to run cutouts on carbed vehicles we had to jet the secondaries quite a bit richer than optimal for the full exhaust. I'm sure the Tundra's ECM is going to protest the cutouts in regards to the short term fuel trim. It's not uncommon to get an occasional CEL on OBD2 vehicles with cutouts.

a082185 · #4 (**permalink**) 04-04-2008, 07:00 PM

Quote:

Originally Posted by thumbster

When we used to run cutouts on carbed vehicles we had to jet the secondaries quite a bit richer than optimal for the full exhaust. I'm sure the Tundra's ECM is going to protest the cutouts in regards to the short term fuel trim. It's not uncommon to get an occasional CEL on OBD2 vehicles with cutouts.

NO CEL HERE!

i've been running my exhaust dumped between the front and rear doors for 3000 miles and it runs and sounds like a champ!!!

ex-chevyguy · #5 (**permalink**) 04-04-2008, 07:12 PM

Quote:

Originally Posted by a082185

NO CEL HERE!

i've been running my exhaust dumped between the front and rear doors for 3000 miles and it runs and sounds like a champ!!!

Good to hear! That thing sounds like a monster!

I wouldn't even be running dumps, it would be a full exhaust going all the way to rear of the truck, it would just be straight pipe, so I don't think I would have any problems. Thanks for the responces, I think I'm just going to suck it up and spend the money on a Corsa sport system and remove the secondary cats.