Alright, here's my situation. Got an 03 cavy LS, stick shift, 58,000km/35,000miles. My guarantee is about to expire as I drive about 600km per week, and now I seem to get the crappiest gas mileage since I've ever had the car. I was comfortably doing about 600-650km per tank the first summer, winter and second winter I had it. Maybe 100km less that first winter that's it. Now this winter I was barely doing 380km/400km, but I had a check engine on and it was the Evap Solenoid that remained open. Now they fixed that, and I can barely get above 500km per tank right now, driving 70/30 Highway/city. What's wrong??? I even try the acetone, it gives me about 50-60km more, but that's it, and when I stop using it the MPTank goes back down.
Now here's my question about air filters. I changed it for a identical stock one at 25,000KM or so. Woud mine be dirty again? If I need to chagne it, am I really gonna get better mileage with a K&N Drop in? I'm not interested in an aftermarket intake.
Would removing the intake bong help even more?
I remember bringing it at the dealer about exacttly a year ago because I was doing @!#$ty MPG, and they said they reprogrammed the PCM, and it did help quite a bit. Now the car has been disconected for 2 m onths when I first left for college, I used it like 3 days, then it got disconnected again for a month. Could the PCM have reset himself to stock gas setting?
Thanks I lot, I'm really tired of doing truck gas mileage, 10-12L per 100km SUCKS in a car that's supposed to take half of that!
Guillaume