I was wondering how well the dme could keep up with engine modifications. So I purchased a wide band sensor/gauge and installed it. My engine is the m20b25 in an e30. Ported head, 274 cam, HD rockers, slightly ported manifold, ported throttle body, Turner chip 173 dme. I just put a set of Stahl headers on with a high flow cat, 2.5" single pipe to a high flow muffler. That is when I installed the wideband and I'm happy to report that it seems to be able to maintain a good afr all throughout the part throttle rpm range. When I go to full throttle it's around 12.3-13.0 or so. I have the miller psik and war chip sitting in my garage but I'm waiting to install it until I have a chance to get to the dyno for some baseline hp and torque values. I'm also swapping to 19# injectors. Up until last week my car still had the stock exhaust from front to rear and I really wanted to change that up before I installed the Miller products. Any way, bottom line is I'm pretty sure The stock tune will be able to keep up with your mods. I'm assuming your using the WAR chip stock tune. A wide band would definitely keep you informed, and they are really not that expensive or difficult to install. And they add that cool factor, no doubt about it. Hope this helped some.