yetihairball

I haven't done it yet, but I'm looking to the future.

It would seem to me that upgrading my mid-pipe and catback exhaust to a wider diameter with less restrictions would lean out my air to fuel ratio significantly. Then, consider adding in a CAI with an upgraded MAF (way too much air, way too little fuel).

My question is to you exhaust upgraders. When you take out the stock mid-pipe and add a new catback, do you also get a tune on your car?

Many people have suggested that I disconnect the battery for some time, install my parts, then reconnect the battery and drive. Supposedly this will clear out my computer's memory and it will automatically readjust the air to fuel mixture. I don't know if I buy it...

So what, if anything, do you guys do to ensure a good ratio...I'm looking at you Mr. Long Tubes No Cats Straight Through Muffler Man. Is a tune absolutely essential with an exhaust upgrade?

redass02gt

no tune is needed for a midpipe. if you disconnect the battery, the computer will reset the stored data from your o2 sensors in the midpipe. when/if you get a check engine light for the 02 sensors, or have an 02 sensor malfunction/shutdown, the computer will run your car off the data it has stored instead of trying to obtain real time data.

for the longtubes, a tune may be needed, it seems like some people have a/f issues with that, some don't.

02StanGT

Bigger exhaust should not lean out your a/f ratio. Bigger exhaust means more area for the same amount of exhaust to cover which means it's less concentrated. Therefore if anything the ratio would be richened.

Car_Ramrod

i wouldnt say you need a tune...but dont forget the MILs/O2 extensions.