Originally Posted by MJB

Sometimes the ECU can't compensate for bolts ons, sometimes it can. Example, my 350z was running dangerously lean in the upper rpm range with just bolt ons prior to my Uprev tune. My spark plugs were burnt up pretty bad as well. After I got it tuned everything was kosher. So IMO a tune is worth it. Yes, you are correct, a tune usually only nets you a few hp, buuuuttt, it also cleans up and sets the a/f ratio where it needs to be, along with other great benefits such as eliminating throttle lag, adjust the redline, ect ect....

OP.. put it on a dyno and see where your A/F is at... guaranteed its going to be lean.