NEED HELP P0507 After Cleaning Throttle Body

[aaronv54]

I've read through several threads on this but I haven't seen quite my situation yet.

I was getting a P0121 "Throttle Pedal Position Sensor → Switch (TPS) A Circuit Range → Performance Problem " so I decided before I replaced anything I would just try cleaning the TB since it has around 147K on it and I haven't cleaned it since I got it with 50K.

After cleaning the TB (left the battery disconnected the entire time, over an hour) I put everything back together and immediately had a P0507. The engine idles very high, around 1500RPM. I have seen some posts that say this is a vacuum leak and some say it is normal until the PCM relearns the idle.

I have driven it about 215 miles since, and it still idles very high on startup. After my drive to work, around 20 miles, it idles closer to 800RPM at a stoplight.

Is there anything else I can check for, is this expected behavior, or does this along with the original P0121 code indicate I just need to replace the TB?

Thanks!

 

[mrrsm]

Using a "Pinched Brake Booster Hose" to see if the Idle drops...

Is there any chance that when you put the Plate back on...that you inverted it 180 Degrees? The Shape of the Air Inlet Venturi is not necessarily symmetrical between the upper and lower air inlet chamber body...and the Baffle Plate could be getting stuck inside of the chamber.

Also... in the same manner as how your Jaw feels after the Dentist has removed your Wisdom Teeth (over-stretched beyond the usual amount it would be at 'WOT') ... the Large & Small Plastic Gears of the Sealed IAC Motor portion of the Throttle Body can get cracked and damaged by accident if opened too wide. If that has occurred, then R&R of the TB might have to be done in the end after all.

 

[Mooseman]

I say you have a vacuum leak at the throttle body or you missed reconnecting the one hose to it. Also check the intake manifold bolts. Disconnect the battery again for 30 minutes.

Another possibility is that the pedal sensor is defective and preventing a normal idle.

 

[aaronv54]

So I had already ordered a new TB on Amazon so I went ahead and replaced it yesterday. I never took the plate off when I was cleaning but did move it around a lot and could have pushed it past its limits.

The idle was high right after I reconnected the battery and started it but then it dropped back down to around 600 and sounded normal. Once I shifted to reverse and actually hit the pedal to reverse it started back with a faster idle, reversing faster than normal after I took my foot off the gas.

The P0507 has returned... I have only driven it around 40 miles at this point, do you think that there is a chance it would get better with more driving or does it sound more like the pedal sensor? I will try pinching the brake booster hose as well and see. Thank you for the suggestions!

 

[Mooseman]

That's why shotgunning parts is a waste of time and money unless it's a known issue (like an sensor failure code).

You were getting a pedal sensor position error code yet you replaced the throttle body, the opposite end of the system.

Look at the video posted above. You have to do proper diagnostics before attempting to throw parts at it. Did you try blocking off the brake booster hose as suggested? Did you look for vacuum leaks? You can use brake or carb cleaner to search for vacuum leaks or even propane.

If nothing is found, unlike the TB, You could do a quick and cheap replacement of the MAP sensor. This would have been a better starting point.

Ultimately, you would need something to get actual live data. A bluetooth OBD adapter and the Torque app for Android will allow you to see the data similar to the video.

 

[aaronv54]

Yeah I do need to upgrade my scan tool, I have an older unit that only can pull codes not data.

I went with the throttle body because I read here that P0121 was the throttle and NOT the accelerator sensor.

The idle issue has only come about since I removed and cleaned the TB, so I didn't think a vacuum leak in some other part of the system would have suddenly appeared. I will check as suggested though.

 

[Mooseman]

I didn't double check the code since you wrote the following:

I was getting a P0121 "Throttle Pedal Position Sensor → Switch (TPS) A Circuit Range → Performance Problem "

So yes, the sensor for that error code is in the TB and may have been damaged during cleaning. The P0507 is likely unrelated.