P0299 - Underboost

[Audiopulse]

I did a lot of searching on this code already but would like some input from you guys.

So, I installed the BSH pendulum mount today... its definitely a little smoother and wheel hop is reduced but I still think this mod is overrated IMO... or I was expecting too much. I really didn't notice any extra vibrations in the car at idle... but there is a little more vibration in reverse. Anyways...

After that I drove around testing it and did some hard pulls and then my car threw a CEL :frown:... went to autozone and this is what it says:

Definition:
P0299 - Turbo/Super charger underboost

Explanation:
Faulty wastegate bypass regulator valve

Probable cause:
Mechanical damage at turbo/super charger
Faulty charge air pressure sensor.

The car still reaches 15-16 PSI, though I did notice it only gets to about 10 in 3rd gear and it seems to fluctuate and go up and down even when my foot is held steady on the throttle. I noticed that my DV is actually a revision C and not a D like I previously thought. Do the rev C valves go bad? Should I start with replacing it with a rev D? The past 2 days or so I noticed the car doesn't seem to be pulling as hard as it did several days ago... I'm going to start with the diverter valve first I think... what is the worst case scenario with this code and with the symptoms I'm experiencing?

Car has 66,000 miles, been stage 1 a little over a month.

 

[gmmills]

Get a revision D - then go from the but it's prob the dv

 

[Audiopulse]

I actually bought a rev D months ago as a "just in case" type of thing so I'll install it tomorrow. If that is the issue would the CEL go away instantly or would I still need to get the code cleared? Autozone didn't clear the code they just scanned for the code.

 

[Spectre]

N75 on the wastegate?

Sent from my HTCONE using Tapatalk

 

[Robert aoun]

You should clear the code so it goes away after installation

 

[Audiopulse]

So I replaced the DV with a rev D and cleared the code with my Driver Programmer. The old rev C looked completely fine so I'm wondering if I have other issues.. I drove around for about 30 minutes and the light didn't come back on. The car feels pretty normal I guess. I think the hot weather and humidity might be why the car feels like its not pulling as hard as it was several days ago... that and I also still need a heat shield for my intake. It gets so hot I basically burn myself touching the pipe. But anyways, I'm going to hope for the best and maybe it won't come back

My million dollar tool


As you can see the old one looks completely fine.. could a DV in this condition throw a CEL? Maybe something internally wrong with it that you can't see?

 

[Audiopulse]

N75 on the wastegate?

Sent from my HTCONE using Tapatalk

I really hope not.. I don't think that's something I could do myself, unfortunately. I'll have to wait and see if the CEL comes back.

 

[Spectre]

Yeah. It's a bitch to get to.

Sent from my HTCONE using Tapatalk

 

[dmsquattro]

I threw that code after my cam and follower were replaced. The cam was not timed properly. Seriously doubt that's what it is in your case based on what you said, but just know that a number of things could cause that code.

 

[Audiopulse]

Thanks. I think it was the DV though. I drove it to work this morning and could feel a difference. Before I replaced the DV I could hear some whooshing noises when I wasn't even pressing that hard on the gas. I dunno... the sounds I consider "not normal" are too hard to explain through text but I think the issue is resolved. Time will tell..

 

[Audiopulse]

For the record, I completely take back my comments about the pendulum mount. After a few more drives around it is definitely a big improvement... basically eliminates wheel hop and shifting in the higher gears is smooth as butter. I went full throttle from a dead stop merging onto the freeway and the smoothness of the shifts was pretty awesome and no wheel hop either . I also haven't noticed ANY extra vibrations at all. Not even in reverse.. or nothing I could notice at least. The only NVH I noticed so far is there is a "thud" type of noise/feel when you turn the engine over.