[StephSD]

2011 Chevy Malibu 4 Cyl 2.4L LT

After doing some other maintenance I noticed how horrible my TB looked so i decided to clean it even getting a new mounting gasket for good measure. Thought I did enough research and it all seemed so easy ....should have known. Besides the fact that it won’t relearn now I have a lean code p0171. I had no codes before (checked with scanner prior ) so I was thinking it had to be the gasket. Took off the tb and I just don’t see how it’s something you could mess up. The gasket only goes in one way and it’s not bent or kinked in anyway. I’m so frustrated. And then I’ve tried everything to relearn the TB : disconnected the battery, disconnected and touched both cables together and waited, I even unplugged the ecm fuse... did all different forms of relearn steps : nothing . Car is actual ok when idling in park it’s when I come to a stop mainly ; rpms rev up to 3k and it jerks back down to 800. I’ll notice some rpm spike when coasting too. As of now the car doesn’t jump and stick at 3k when I turn the car on like it did initially.
I have an appt in a few days to go to the mechanic so they can do it for $180 - ouch. Thought I was doing myself a favor by doing this but here I am now. Any advice would be appreciated.

 

[DrivenDaily]

Quick question or two...

Did you spray cleaner into the TB and then wipe it down, or did you spray the rag and then wipe the TB?

This revving when coming to a stop: Is the engine already at 3ooo as you're slowing down, or is it slowing as you do and then suddenly revs up to 3ooo?

The reason for the first question is that the motor that moves the throttle plate is in that little chamber with the plug. If any cleaner got inside there, it could have caused issues with the motor. I'm not sure if the motor is available separately or if you'd have to replace the whole TB, but the whole TB is most likely.

My thinking behind the second question is that the learned behavior of the TB can't be reset with the same tricks you tried, although those were intelligent things to try. Kudos. I had my TB cleaned by a dealer tech that I visited back in 2019. After cleaning it, he hooked up his computer and had to go to a specific property and manually set it to zero. Over time, the ECM will adjust the action of the TB due to build-up on the butterfly and/or throat. When you clean it, it doesn't know that so it will move the throttle to the learned position. This could explain the wild revving and jerking. I'm not sure if it can explain the PO171 or not.

 

[StephSD]

Quick question or two...

Did you spray cleaner into the TB and then wipe it down, or did you spray the rag and then wipe the TB?

This revving when coming to a stop: Is the engine already at 3ooo as you're slowing down, or is it slowing as you do and then suddenly revs up to 3ooo?

The reason for the first question is that the motor that moves the throttle plate is in that little chamber with the plug. If any cleaner got inside there, it could have caused issues with the motor. I'm not sure if the motor is available separately or if you'd have to replace the whole TB, but the whole TB is most likely.

My thinking behind the second question is that the learned behavior of the TB can't be reset with the same tricks you tried, although those were intelligent things to try. Kudos. I had my TB cleaned by a dealer tech that I visited back in 2019. After cleaning it, he hooked up his computer and had to go to a specific property and manually set it to zero. Over time, the ECM will adjust the action of the TB due to build-up on the butterfly and/or throat. When you clean it, it doesn't know that so it will move the throttle to the learned position. This could explain the wild revving and jerking. I'm not sure if it can explain the PO171 or not.

Yes, unfortunately I sprayed the cleaner directly into the TB (just like I saw A bunch of people doing in videos 🤦🏻‍♀️) it wasn’t until trying to trouble shoot that I came across that tinyyyy little detail that seems to make or break or you.
The revving and jumping up to 3k will happen while I’m driving at higher speeds then coming to a stop (so yes, I was originally at higher rpms) and also if I’m going slower like in my neighborhood and it’ll jump up to 2k or 2500 at a stop.
From what I’ve researched gm made this throttle body and tb sensor as one unit. Apparently you use to be able to replace the sensor by itself but with this 2011 you have to by a complete new unit (of course, eyeroll). I heard that when people replace the brand new throttle body/sensor that they have to end up taking it somewhere to do a relearn anyways. I would hate to pay for them to attempt it on this one only for the sensor to be the problem and it can’t be done. Then have to pay for a new throttle body and another relearn. I’m so mad that I even ended up doing this now. This is one of the easiest things to do as far as accessibility and time but it has caused me the most problems and time afterwards.

btw for anyone who might be reading in the future with the same problem: this make and model, 2011 Malibu, doesn’t have a idle air control valve. I read lots of suggestions about this that might be a problem and may need to be cleaned only to realize my car doesn’t have one.

 

[DrivenDaily]

Yes, unfortunately I sprayed the cleaner directly into the TB (just like I saw A bunch of people doing in videos 🤦🏻‍♀️) it wasn’t until trying to trouble shoot that I came across that tinyyyy little detail that seems to make or break or you.
The revving and jumping up to 3k will happen while I’m driving at higher speeds then coming to a stop (so yes, I was originally at higher rpms) and also if I’m going slower like in my neighborhood and it’ll jump up to 2k or 2500 at a stop.
From what I’ve researched gm made this throttle body and tb sensor as one unit. Apparently you use to be able to replace the sensor by itself but with this 2011 you have to by a complete new unit (of course, eyeroll). I heard that when people replace the brand new throttle body/sensor that they have to end up taking it somewhere to do a relearn anyways. I would hate to pay for them to attempt it on this one only for the sensor to be the problem and it can’t be done. Then have to pay for a new throttle body and another relearn. I’m so mad that I even ended up doing this now. This is one of the easiest things to do as far as accessibility and time but it has caused me the most problems and time afterwards.

btw for anyone who might be reading in the future with the same problem: this make and model, 2011 Malibu, doesn’t have a idle air control valve. I read lots of suggestions about this that might be a problem and may need to be cleaned only to realize my car doesn’t have one.

We've all learned lessons the hard way at times. Sorry this was how you learned it.

When DBW (drive by wire) replaced the throttle cable, it also replaced the IAC valve. I'm just glad mine doesn't have EGR!

Shop around the dealers and see if you can befriend a tech. It's a very simple process that takes very little time. He/She just might accept a decent dinner or some of their favorite brew-skis, and you'll have gained an invaluable resource for the future!

 

[StephSD]

We've all learned lessons the hard way at times. Sorry this was how you learned it.

When DBW (drive by wire) replaced the throttle cable, it also replaced the IAC valve. I'm just glad mine doesn't have EGR!

Shop around the dealers and see if you can befriend a tech. It's a very simple process that takes very little time. He/She just might accept a decent dinner or some of their favorite brew-skis, and you'll have gained an invaluable resource for the future!

Ended up having to take it in to a local shop that has a tech come in . Did the relearn for $160. Left the shop and it was much better but noticed some hesitation and hard shifting when trying to accelerate (especially going up hill). They wanted me to drive it for a few days to see if anything changed . The only thing that changed was a new code showed up p0010 camshaft position actuator . It has since went away after driving for a few more days. I have to take it back in but I’m afraid I messed up the sensor with the spray ? Ugh

 

[DrivenDaily]

When you return, hopefully another scan will be covered by your earlier work. It would also be nice if it all works right from now on.