Eating gas

Papa Rad17 · 03-23-2014, 12:08 AM

not quite an alero but my room mates sunfire has the same 2.4 5sp that came in the aleros. We've only had for a week so far, just replace the intake air temp sensor and the cams/ cam sensors/plugs, pretty much a full tuneup was done before we got it. We thought the intake air sensor was going to be the last of it but he just took it on the road and it threw a code again as well only getting 14-16 mpgs on the highway. Assuming its the same code as before its a misfire on banks 1 and 2. Im thinking the next place to start is the upstream 02 sensor. what else?!
also Only two times in the week we've had it so far its ticked upon start up, im pretty sure its the timing chain tension problem as is common with this motor. shurly that wouldnt through it off THAT much though right?
I dont know this twin cam like i did my old ecotec, any help is appreciated, we need to get the last few kinks worked out. Thanks in advance.

Papa Rad17 · 03-23-2014, 12:42 AM

Just went out and had him start it up for me. It turns right over, purs like a kitten, hauls ass like its running fine to. I can hear a hiss though, sounds like a vacuum leak to me. I checking everything to/from the brake booster and around the throttle body, everything seems to be in great order. hoses have been maintained from what is visible. any ideas? I'll get more info on the code it threw tomorrow.

03glgold · 03-23-2014, 09:54 AM

check the map hose at the throttle body...on my friends 01' alero it had essentially turned to powder and it was running like crap...replaced and it does great

a.graham52 · 03-23-2014, 10:04 AM

verify a tune up was done and done right. when i first get a vehicle thats the first thing i do. remove spark plugs and replace with new if they wernt done, change plug wires, fuel filter, air filter, clean the throttle body etc. with the vacuum leak, feel around the engien with it running and you know you will hit it when the noise changes.

fisdad · 03-23-2014, 02:35 PM

I would take out the ICM and have it tested. Also test the coils. And mine was having issues with the Idle air control valve sticking as well as the TPS

MMGT1 · 03-23-2014, 05:47 PM

If your hearing a hiss, Id be finding the VAC leak. As Ive said a thousand times to people, a can of break cleans is your best friend when you dont have a smoke machine to hook up. graham has the right idea there too, good advise. I would add, when you pull the plugs to check them, check the number on them and make sure the right plugs were installed at the proper gap

Papa Rad17 · 03-24-2014, 12:21 AM

Thanks all. Hopefully I will time to look into it more thoroughly tomorrow.