GenVibe - Community for Pontiac Vibe Enthusiasts

Ive been battling my ECU for a while. Basically I have to reset the ECU every 100 miles to get the best mileage. If the ECU runs too long without a update the mileage tanks. I was wondering would it be a good idea to get a newer ecu (out a 2005/2006) . Not sure what else to do lol, any ideas?

That's a weird one dude.You might want to check a few things first.A clean maf sensor,Good air filter,oil change,restricted exhaust(probably cat converter),PCV valve.To me it sounds like you have a problem somewhere else,and the ecu cannot compensate for it.

Mods? If you've got an intake and/or exhaust, it could be running lean until the ECU adjusts. Better mileage but less performance for 100 miles or so. If not clean your MAF especially if you've gat an oiled filter. Other than that I don't have a clue.

yeah this sounds deeper than a ecu. I think theres a underlying couplret here, do what these guys stated above. ecu's are expensive and usually dont go bad..(usually)

MAF was replaced once & CleanedPCV Was cleaned but might get it replaced.Air Filter Cleaned & its a K7N Drop inNo mods cuz they dropped mileage too muchOil changed with Modil 1 Syn.Im suspected a bad CAT also, so im getting a JP midpipe at the end of this month. Other than that Im lost too.Was thinking about getting a new ecu because each year the Vibe mileage goes up

ohhhhh bad cat's do dirty things like that! just take it off hahha sounds like you've done some investigative work yourself! awesome...mmm what about spark plugs are they dirty? vacuum leaks in some hoses? you'll usually hear a hissing noise. btw where did you order a JP midpipe, their site never really listed one....and ive been looking into one for my exhuast system. do you have a base or GT vibe>?

how bad does the mileage get?

You have to use the ECU for your year of Vibe. You can't use an '06 ECU on an '03 for example. For one thing, the '05 and '06 are drive by wire.

What kind of gas do you use? Do you get it at the same place everytime? What octane do you get?How hot is it by you?Like tcam asked, how bad is it? Wierd... Northvibe,You have to call Jp Performance and order it. It's a 'custom' order. It's what I SHOULD have done.

I bought a replacement ECU when I got my UNICHIP. Got it for like $55 on eBay. Just have to make sure it's for your generation, transmission, etc.

if no one minds me asking....how much is the JP down pipe? I was trying to price out exhaust: ported headers, down pipe, and cat back exhaut (magnaflow)

I'd clean the MAF again. The drop ins can lose oil very easily after a cleaning. Real easy to over oil and their proximity can compound the issue.

JP Midpipe is around $500 & its custom made from what I heard because you have to call them to make one Takes about a month. I got really lucky with a used one thats only $200 I have a base vibe115F All Day100F All night -Las vegasI have a Base 03. Mileage will be as bad as 26 MPG. 100 Miles after Reset I average up to 31-32. Im Using shell gas only because that give the best mileage & performance.

Remember, Northvibe, if you buy the JP Midpipe then you only need an axle-back exhaust, such as Vibrant or Borla. The Magnaflow has the resonators and extra piping that the JP Midpipe would already have. You could buy the Magnaflow but the second piece could not be used.

What octane do you use?The Hot (crappy) air might have something to do with it. And are you checking mpg using the same routes each time, or are you just taking readings from random trips? Like one trip your just running errands around town, the next you driving to the next city.Oh!! Is your A/C on all the time? That alone could be the cause. I know my a/c zaps like half the power out of my car. Hardly use it anymore because of that.

Quote, originally posted by ProtonXX »115F All Day100F All night -Las vegasI have a Base 03. Mileage will be as bad as 26 MPG. 100 Miles after Reset I average up to 31-32. Im Using shell gas only because that give the best mileage & performance. that's not that bad at all. I get 24mpg almost all of the time. I drive agressively though, and live in just as bad of heat as you do.

The is A/C on all the time, but I got a OBX Alt +crank pulleys & did some vent tweaking so its on/off half/half . Im Using 87 Octane in the city and 91 on long road trips in cali.I did notice I get the best mileage at night.

Wow! I just looked at some of the stuff you've tried, Proton. If you've lost mileage, it's probably not the ecu. I'd look for a leak in the intake after the MAF or something that may not have been put back 100% from one of your tests. Hose from PVC or something like that.