I have just purchased a new 2005 Accord 4-cylinder auto se coupe.I wanted to install a cold air intake and a cat-back exhaust. I read an article posted by Sport Compact Car stating that Toyota's, Nissans, etc. use MAF monitoring monitoring the fuel injection system and can accept cat-backs and cold air intakes with no tuning changes. The MAF directly controls the computer and adjusts for the proper fuel/air mixture. Well my 2005 has an additional device which complicates the issue, a speed density system. My Honda and Acura's use a MAP sensor to help the ECU determine how much fuel to inject for the correct mixture. Since these to devices must calculate airflow based on the pumping efficiency of my stock engine. If I increase the pumping efficiency of the engine the article states that speed density systems do not COMPENSATE for modications VERY WELL. They recommend a fuel pressure riser that goes in the return line to the gas tank from theinjectors. They also say, for best results the riser should be tuned on a dyno. My goal by adding the items mentioned is to increase my GAS MILEAGE during normal driving and have a little surprise to use rarely. But still feel good about my car. I have always added cat-backs and cold air intake to my Toyota's with great results. I had a 98 EX Civic injected and added the to devices mentioned and the check engine light would come on and I was routinely having to pull the engine fuse to reset the ECU. The Civic burned rich. I guess I'll just have to leave well enough alone and drive it the way it is.

 

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<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by i3igpete &raquo;</TD></TR><TR><TD CLASS="quote">?</TD></TR></TABLE>
agreed... ?

 

i think i know what your getting at....however

fuel maps are not set in stone from the factory. the ECU is able to manipulate and relearn curves based on the conditions it recieves from the numerous sensors. if you free up air flow by way of an aftermarket intake and exhaust, the ECU will sense this chance in air flow, and will adjust the fuel curve (mainly under heavy load) accordingly