I've got a P0120 error code on my 2005 manual, which I've frequently seen reported as a throttle position sensor error. I ran by the dealer and a service tech quickly read the code and told me a valve in the intake was stuck and service would require removing the intake to fix/replace it, which would take 1.5 days and $600-$700.

Has anyone here had this particular issue before and what was your resolution? Should I go ahead with the service technician's recommendation or should I consider/try less involved and less expensive checks and fixes first?

Thanks.

Randall

 

The P0120 isn't in our shop manual, but Google results all appear to point to the throttle body.
I doubt its the stuck valve your tech was talking about because that tends to generate a P2070 code.
Unless he read a pending code that listed this also...
Did you get the P0120 from the dealer or was this a hand-held device?

 

I got the P120 from a handheld. I did not think to ask the tech if he got the same code or not. Is it possible that my device is misreading the code?

 

Its a variable to rule out... I would ask the tech what the code was he received.

 

About a year ago my throttle body butterfly valve was getting hung up ( I attempted to clean it but no luck and I can't remember the CEL# it was giving me). At first it just started with a CEL, however, after a week or so the RPM would spike during start up and when stopping. Are you experiencing any unusual RPM's?

Edit: FYI, they replaced the throttle body under warranty. It took them one day and if I recall correctly their material estimate was roughly $600

 

I haven't had any RPM problems. On the contrary, my 8 has been running better since the CEL appeared. It was cutting out while going through higher RPMS, but now it runs to 10, I mean 9K very smoothly. I asked him if running it with the stuck valve was a bad idea and he said at worst, it would use more fuel and even said it was a good idea to run it hard and see if the valve frees up.

I made the reading using CARMAN (http://openbossa.indt.org/carman/) on a Nokia N800 using a bluetooth reader (http://www.dealextreme.com/details.dx/sku.16921)

If it is a stuck valve, is there a fuel additive that might possibly free it?

Thanks for everyone's replies.

 

Fuel additive... no.
But there are solutions if its really a stuck valve, but we need to know what valve before recommending anything.
And we need to know what code he was referring to in order to know what valve.
A stuck valve can also cause power loss/hesitation and even allow your engine to stall (which is worse case that I've seen with a stuck valve).

There are methods we can do to start troubleshooting the intake valves, but I would hate to ignore the throttle body code you received without knowing for sure it was just "mis-read"

 

The correct code is P2070.

 

The CEL went off about a week ago and hasn't come back on since. I did drive it hard for about a week prior, but I don't know if that helped or not. It's running very well now. Shortly before the CEL came on, it was cutting out from 5K->9K. While the CEL was on, it stopped cutting out, but seemed to sputter at cold idle and I even think I heard it backfire a few times. Now it's running perfectly.

 

Good to hear... if that code ever comes back, refer to this thread to start checking components related to that code:
https://www.rx8club.com/series-i-do-yourself-forum-73/diy-remove-ssv-beta-teaser-video-184663/