Hi everyone. New to the site. I am going to jump right in. I have a frustrating P0507 code on a 97 Bonneville SE. This light popped on after I had a tune up and rack and pinion replaced. I have replaced IAC. Removed and cleaned TB. Checked for vacuum leaks. Changed PCV valve with o-ring installed on PCV valve. After clearing code it popped on after seven miles. When I changed PCV it popped back on after 26 miles. After TB cleaning it popped on after 18 miles. Prior to anything being replaced or cleaned it idled@ 2000 rpm. After PCV valve it was around 1600 rpm. After TB cleaning it idles@ 1000 in drive and around 1100-1300 in park. I am at a loss of what else could be wrong. Need some fresh ideals before driving it into a river. Thanks in advance for suggestions and replys.

i would go over the vacuum tubes again. its tough to see sometimes, start the engine and spray carb cleaner or similar around tb joints and where it goes from metal to rubber and back and listen for pitch changes

See if this helps.

https://www.gmforum.com/obd-ii-trouble-shooting-153/p0507-284091/

I might fade a little heat for this, but unplug the TPS and start it. Does it still idle high (after warm-up)?

Smoke..... I unplugged the TPS and it idled higher for about four seconds and went back to 1100 RPM. i rechecked wires and secured plug-ins. I still have to re-spray for any signs of leaks.

Ok so been driving the car and idle has dropped to 900 rpm in drive and 1000 rpm in park. The check engine light has stayed off so far. It is the longest it has stayed off. Hopefully it will continue to adjust.

Don't know if this helps but the rpm'* surge between 2000 and 2500 when accelerating on the highway. Not all the time but it does it quite often.

Sounds like your torque converter is unlocking/locking.

1. Remove the engine oil fill cap on the valve cover.

2. Check for excessive vacuum on the crank case. NOTE: It may be hard to remove the oil cap with the engine running.

3. Check for a missing Positive Crankcase Ventilation (PCV) valve or large o-ring that goes around the valve.

4. Block the PCV valve hole and see if the idle speed comes down and recheck vacuum.

Tech Tips:The PCV valve is under the Manifold Absolute Pressure (MAP) sensor.

Number 1 cause I see is missing o rings on Pcv valve.

Bill even though we welcome your valuable information, the above post is 7 years old & chances are the original poster is no longer participating.
Please read our site rules regarding Bumping old threads, (Don't reply if they are older than 6 months)
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