Hey all. I figured I'd post up an issue to see if I can get any help. My rebuilt was complete about 5 months ago, and last week was the first time I've taken it on any trip. There's about 3k miles on the rebuild. Other than that, there's been no changes to any mods. I've been getting ridiculously terrible mileage with it. Between 15 and 17mpg with the cruise set at 70-75 on the highway. A far cry from ~25mpg I was getting last year. Hell, in the city it's been getting over 20. I stopped for gas and when I started it up again, I got a CEL. I checked it at Oreilly's and it was a lean code. I cleaned the MAF and put in a new air filter but no change. The code seems to like to come back if I stop for a short period of time and restart it warm. Like, getting gas or food. I checked today for any kind of vacuum leak or boost leak but I couldn't find anything. I retightened the clamps on any hoses I could find for good measure. Any other ideas?
It's a 2010 WRX. Rebuilt by RS Motors with forged rods and pistons. No other motor work done to it. Mods are just a tune and a catless turbo-back. It was tuned before I bought it, so no idea who tuned it. I got it a year ago and there's now 51k on it.
Your car is running fine though? No rough idle or sputtering under acceleration? I would check your O2 sensor. Short search revealed that. Your primary or front o2 sensor.
Yep, it runs and idles fine. Just gets weird on long drives. I think I found that in a search too. I just thought I'd ask around before I spent $200 for the sensor. Maybe after my drive today I'll order it and change it this weekend.
