2007 HHR LS 2.2 163K

Hello, new here. Have a problem. started on a cold day Eng Pwr Reduced, and changed the thermostat. Apparently solved problem. But at certain rpms (2500-2900 ) noted hesitating. Drove 1700 miles trip like that. Always up to 3k rpms. Stop for gas and get the problem again. Now I get the p codes 0121 and 2135 about the throttle body, noted it has 6 wires. Question. Tps has two sensors in the same body? Can I discard gas pedal sensor?
Thanks

 

"Can I discard gas pedal sensor?" do you mean "discount" rather than discard?

 

Yes, eliminate from my suspect list.

 

You may be able to discount the TPS being "out of range" only after you make sure you've attended to the other issues.

Some OBDII trouble codes are known to "Daisy Chain", in other words, one fault can have a cascading effect causing spurious trouble codes to be set.

 

Check the link in my Sig.

 

Welcome to the site!

 

Donbrew, you don't seem to have a sig now.

 

he must have got'n the boot!! or was that Donbrew1 .

I did a little Googleing and found most people who have asked about the P0121 code have been given recommendations but don't return to confirm the issue has been fixed.
I suggest to disconnect the battery neg cable and check the wire harness connection at the throttle body and while you ere there remove the TB and gently clean both sides of the butterfly with Throttle body cleaner, Please NOTE: Do Not move the butterfly as it may damage the throttle body internal gears.
Ensure your MAF sensor connection is clean and tight.
Please let us know about your progress.

The P2135 may be a code triggered by the first code, and could be loose wires in the TB connection.

 

I kept getting a P0121 code and what finally fixed mine was a good TB cleaning. Unbolt the TB and place a towel between the TB and manifold (leave connections connected). You will need a 2nd body unless someone else can state how to open the TB blade in another fashion (don't try to open with your fingers). But you will need someone to turn on the ignition (DO NOT START) and slowly press the gas peddle as you spray TB cleaner on the blade and side walls. The TB blade will open electronically. Once cleaned, turn the ignition back off, lift TB back up to remove towel, be careful not to dump into manifold. Bolt TB back down.

Mine rans very nice afterwards.

 

Tanks everybody.
I reset the computer and the codes are gone.but they come again ��. A Lil of history. The first time engine Pwr Reduced appear, came with the temperature code. That's why I changed the thermostat, and it helped. When I start my hhr every was fine, idle is not rough. So I take the interstate and apply the cruise control. Again under 70 mph or between 2500-2900 rpms noted feel the hesitation. At the beginning I thought was the transmission (can happen), so I drove above 70 kph for about 1100 miles and at the last stop for gas again the check engine light and hesitation on the acceleration appeared. Keep driving with no cruise control, the same above 70 75 mph and fine. Next day engine light vanished and drove 600 miles ok with no cruise control. Reached destiny, stop my car for 2 days. And started the car in the morning at normal idle an visual inspect on the harness connections everything looks OK and then I did an acceleration in park to the bottom of the pedal. And again the check engine light and the message Engine Pwr Reduced. Went to auto zone as is 20 mph max and get the codes P 0121 and P2135. There is no rough idle until I reach 2500-2900 rpms. Thanks