Rough Idle...code P2128 - GM Forum - Buick, Cadillac, Chev, Olds, GMC & Pontiac chat

Buick When starting new posts, please specify YEAR, MAKE, MODEL, ENGINE type, and whatever modifications you have made.

Thread Tools Search this Thread
Old 07-07-2014, 07:52 PM   #1
Junior Member
Thread Starter
Join Date: Jul 2014
Posts: 1
Thanks: 0
Thanked 0 Times in 0 Posts
Mobious03 is on a distinguished road
Default Rough Idle...code P2128

I have a 2004 Buick Rainier with the 4.2L I6 2wd. It has a 135,000 miles and I recently changed out the spark plugs and while doing so, I noticed some oil on the a few of the plugs. I did some research and decided to changed the valve cover gasket. My dad and I purchased a manual for the engine and was able to change out the gasket after many hours. We also changed the intake gaskets since it was torn apart. The repair went back together with out a problem and all the connectors, hoses, everything was reconnected. The car started up and would idle rough for a few minutes then die. It also two engine lights showing on the dashboard. Did some research and decided to do a manual reset of the computer. Held both disconnected battery cables together for 30 seconds then reconnected. Car started fine and ran fine. Drove it probably 70 miles after I did this and had no problems. The car sat overnight, and in the morning would start, idle rough, then die. Also, one engine light came on in the dashboard. Finally got the car to run and it eventually smoothed out and ran fine. Took the car into the local mechanic to have the code ran and he couldn't get to it that day. It sat there overnight and the next day when I called him he said the car started and ran fine. He ran the code and it came back as a Cam Phaser code. He did not give me the actual code and I could get that code probably Monday. Anyway, I had him just reset the code and he drove the car to my house. The car sat for 7 days and when I finally drove it again it started right up and ran perfectly. Drove it 40 miles and had no problems. Came home, shut the car off, drove it again later in the evening, no problems. The car sat overnight and this morning, when out to drive it and it started, rough idled then died. An engine light also came on again. I needed to drive it so I did another manual reset of the computer and it started and runs fine now. Went to drive again after the car sat overnight and same thing happened. Started, idled rough then died. Two lights came on in the dashboard. One was a check engine light other was the lower power light. Ran the codes at O'reillys and it was P2128..

Car starts and idles fine today but stays in the low power mode.

I do not know what the problem is. Electrical/Computer? Mechanical? Any help would be greatly appreciated.
Mobious03 is offline   Reply With Quote
Old 07-07-2014, 10:51 PM   #2
Senior Administrator

Certified Car Nut
Mike's Avatar
Join Date: Jul 2003
Location: Horseheads, NY
Posts: 15,647
Thanked 999 Times in 775 Posts
Mike has a reputation beyond reputeMike has a reputation beyond reputeMike has a reputation beyond reputeMike has a reputation beyond reputeMike has a reputation beyond reputeMike has a reputation beyond reputeMike has a reputation beyond reputeMike has a reputation beyond reputeMike has a reputation beyond reputeMike has a reputation beyond reputeMike has a reputation beyond repute

Something to do with your accelerator. Which is DBW. I hate them.

It doesn't hurt to try and do this, but give this a try if your willing to pull your gas pedal out...

Temporary DIY Fix Instructions for 05 Pedal - Forums
Mike is offline   Reply With Quote

Related Topics
Thread Thread Starter Forum Replies Last Post
update to rough idle...code P0300 DoubleAA53 2000-2005 1 11-16-2008 06:06 PM
P0131 code and rough idle Shaneomack8 1992-1999 17 03-26-2008 04:15 PM
Code 18, Rough Idle shortstuf212559 1992-1999 2 10-24-2005 01:55 PM
From rough idle to high idle randman1 1992-1999 25 09-07-2004 09:20 PM
'00SSEi:rough idle,high idle...Please Help.... GTP2SSEi General GM Chat 2 07-29-2003 01:46 PM

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

All times are GMT -4. The time now is 12:38 AM.

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to and affiliated sites.