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Discussion Starter #1
If I think my cobalt is not running as it should (feels sluggish) What can I do to test it?

I mean can I dyno it? what do i look for?

My balt is a 07 LT 2.2 with a 40t4e.
 

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=\ mine feels sluggish aswell. idn what it is. like i press on the gas and the engine sounds deeper, but the rpms dont go up when im in like 3rd and 4th gear. i gotta really push it dont, then it doenshifts, then shifts again and i can go through the gear properly.
Sometimes when i push down the throttle the rpms will decrease, and when i let off the throttle the rpms will shoot up like 300 rpms. QWTF!
 

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Try this...run a scan on your OBD II and then do an erase (even if there are no codes).

All Cobalt owners need to know that the ECM "learns" how you drive. It adjusts to the way that you drive. If you have been "babying" it it will adjust to being "miserly". Doing an erase will set all the learn values back to the original and you can "relearn" the car to run better. Disconnecting the battery doesn't do the relearn feature.
 

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Wouldn't hurt to run a bottle of Chevron Techron Concentrate if you haven't done so recently.

or other complete fuel system cleaner if you prefer.
 

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im at 33k miles. So how do we reset the ecm?
 

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Discussion Starter #8
Ok Im at 41000KMS dealer changed fuel sensor and fule pump and I noticed performance drop the second I left the dealer. Will try OBDII reset thanks.
 

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Discussion Starter #10
So what do you do then? My fule guage was not accrate. Took car in they changed sensor. took car home and guage was good car would loose rpm under heavy rpm took car in they said nothing was wrong (i had refulled) problem came back when i was 1/4 tank took car in they changed fuel pump. Car now sluggish
 

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Any scan tool that can read your codes AND has an erase feature on it will work.

You have to follow the directions of the scan tool. Some are simply hold the erase button for 2 seconds, and when the scan tool asks "erase?" you hold it down for 2 more seconds and then it erases the codes and resets the learn values.

BTW I am getting this (reseting the learn values) out of the factory Cobalt service manual...not something I've been told!

My 06 LS used to do that...seem like it was sluggish, especially off-the-line. When I erased the codes it would spin the tires again. I periodically do an erase on my SS/NA too...I can tell by the exhaust note at idle when it is time.
 

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=\ mine feels sluggish aswell. idn what it is. like i press on the gas and the engine sounds deeper, but the rpms dont go up when im in like 3rd and 4th gear. i gotta really push it dont, then it doenshifts, then shifts again and i can go through the gear properly.
Sometimes when i push down the throttle the rpms will decrease, and when i let off the throttle the rpms will shoot up like 300 rpms. QWTF!
Sounds like a clogged cat.
 

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Discussion Starter #14
Ok so I did a odbII erase and it worked!!! I had no codes too weird. Now one las question I was pushing my balt hard and the tires spun while I was doing about 80. My rev limiter came on is that normal? Shouldnt the car have just shifted rather than rev limiting?
 

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Ok so I did a odbII erase and it worked!!! I had no codes too weird. Now one las question I was pushing my balt hard and the tires spun while I was doing about 80. My rev limiter came on is that normal? Shouldnt the car have just shifted rather than rev limiting?
You have an automatic right? Then yes the car should have shifted instead of hitting the rev limiter. In fact I've never heard of an auto hitting the rev limiter. Are you running any trans mods like shift plus or did you have it in a low gear instead of drive?

Edit: you didn't hit the speed limiter did you?
 

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Discussion Starter #16
Yes I have an auto transmission. If the road is wet and I really step on it and when in second my wheels spin it revlimits rather than shifting to third. This only happens when my wheels slip otherwise operation is fine. Its not traction control cause my LT1 does not have traction control. Is this normal?
 

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Discussion Starter #18
my cobalt does not have ABS and does not have traction control... Im not guessing Im 100% sure my car is not traction control equipped. My friends is mine is not
 

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When you put the tranny in "L" do you get a TC light on the dash?

If I have my tranny in "L" and get going normal then punch it at about 15 MPH my engine will hit the rev limiter for a split second as it shifts into 2nd. Is that what you are doing?
 

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Discussion Starter #20
No if I put it in L i dont get the traction control disabled light. When I bought my Cobalt new I ordered it without traction control. I did not like trac control on my old Z24 and was happy I could get my cobalt without it.

Now what is happening and I never noticed it before I took my car in for repairs is if im still in first or second or even if i spin from dead stop when the car redlines rather than jumping to next gear the rpm cuts down to 4000RPM.

My car is as follows 2007 Cobalt LT1 with Auto trans no ABS no traction control.
 
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