Need help TGV sensor

I recently bought a 2002 WRX and I found out that the previous owner deleted the TGV sensors and the codes. The other night I decided to step on it and I realized that the car would lag when it hit higher rpms and it would not go faster until I changed the gear even though it was not at high rpms. It felt as if the car would let go of the gear and just rev without advancing and then my check engine light came on and it began to flash . My uncle then connected a machine to it and he said that it did not have any codes witch indicated that the previous owner deleted them. So I began to research why my car began to lag and drive the way it did and I'm thinking its because I got a CEL and my car is on "LIMP" mode. Is that the problem? If so do you guys know how I can I fix this problem? I am new to the subi thing so I have no Idea please help.

If the TGV were deleted the previous owner should have had the car tuned. This certainly means it wasnt tuned.

***please advise from driving the car hard. Only normal driving from point a to b if this is your daily***

Wait for the others to chime in.
[MENTION=1]IGOTASTi.COM[/MENTION] [MENTION=662]Batmobile_Engage[/MENTION] [MENTION=1507]Spamby[/MENTION] [MENTION=9]HolyCrapItsFast[/MENTION] [MENTION=4577]TK-421[/MENTION] [MENTION=652]Grinder34[/MENTION]

The worst thing a TGV delete would do is it would produce a number of cell's related to the TGV mechanisms if it is not compensated for in the tune, but it should never impede performance. If I was to guess I would say that you have a leak somewhere. The only way TGV's will impede performance is if they were still installed and are not functioning.

Anything is a guess really with out going through some troubleshooting steps. Do you have an AccessPort or a Tactrix? It would really help if you can monitor some specific parameters and post a log.

To check for leaks, you could start with visual checks. Then if there are no obvious leaks you can spray some carburetor spray around while the engine is idling and listen for changes in idle speed. If that doesn't work then I recommend a boost leak test be performed and that can be done by a local performance shop. From the description you provided I might think there is a leak while under boost.

Also can you tell us what P0 code it was?

The other observation I could make is if you are stepping into the gas and your RPMs are climbing but the car is not going faster, then that is clutch. Sounds like you might have multiple issues here.

HolyCrapItsFast said:

The worst thing a TGV delete would do is it would produce a number of cell's related to the TGV mechanisms if it is not compensated for in the tune, but it should never impede performance. If I was to guess I would say that you have a leak somewhere. The only way TGV's will impede performance is if they were still installed and are not functioning.

Anything is a guess really with out going through some troubleshooting steps. Do you have an AccessPort or a Tactrix? It would really help if you can monitor some specific parameters and post a log.

To check for leaks, you could start with visual checks. Then if there are no obvious leaks you can spray some carburetor spray around while the engine is idling and listen for changes in idle speed. If that doesn't work then I recommend a boost leak test be performed and that can be done by a local performance shop. From the description you provided I might think there is a leak while under boost.

Click to expand...

I dont have a ap or a tactrix ive heard of them but i do not know how to use them. Do you think tuning the car will help this problem? And thanks for the reply

Like [MENTION=9]HolyCrapItsFast[/MENTION] said there could be separate problems. Clutch and a leak. Rule out the leak before we move onto the clutch.

Does that slippage feel occur only when youre getting on it?

Also how many miles and what exact mods do you have from what you can tell. (Pics help if youre unsure)

Definitely seems like more than one issue to me. Maybe it's just me, but I find it difficult to understand the symptoms unless I'm in the car or maybe see a video of it. As others have said, the engine continuing to rev while not really going any faster makes me think the clutch is almost toast. There should definitely be a CEL Code that can be read, seeing how the car is in limp mode. Having that code would be one of the best places to start.

There are some TGV deletes on the market that have been known to be faulty, for instance if it was replaced with a cheaper composite TGV delete the actual composite housing could be cracked. Or there could be a gasket failure in any number of locations after the throttle body that would cause this issue. Your uncle's computer will always read that their is a TGV sensor code. If I hooked my Snap On Modis up to your car it would read the samething. But what it seems like is this car has an Opensource tune, and the previous owner went in with ECUFlash and just disabled the codes from triggering the CEL to come on for that particular parameter. Even though any scan tool will still read it as a faulty code. As [MENTION=9]HolyCrapItsFast[/MENTION] mentioned, with something that has modifications to this level, it's important to know what's going on with the engine as a whole. We can help you diagnose this problem in further detail with data logging the car.

And I do also agree with [MENTION=662]Batmobile_Engage[/MENTION], this does seem to be more along the lines of a mechanical issue. A leak like he said will cause a loss of power, especially when boost pressures enter the manifold and pressurize it. If there are failing gaskets that would be a tall tale sign for where your problem may here in lie.

One thing you should really consider doing is a Boost Leak Test. This test will pressurize the intake system and allow you to check for leaks anywhere with in the intake track.

A scan tool, is not the end all do all tool. There have been plenty of times where a scan tool has led me down a rabbit hole, and if good old fashion exploratory investigation happened, a major frustrating headache could have been avoided. For instance, had a car come in with a misfire code, as the scanner said. Pulled the plug, plug looked fine. Started looking at the coil pack, checked resistance to the coil. Coil was fine. Looked at the rubber boot on the bottom of the coil, and it had a small pin hole in it, was leaking electricity through the hole in the boot and grounding out on the spark plug well. Replaced the boot and the car ran fine. But had I just went with what the scan tool said, it would have cost the customer $205.00 for a coil pack, instead of $5.00 for a new coil pack boot.

A little investigation and leg work, like data logging or a boost leak test could save you hundreds in parts and or labor charges.

I hope this helps you out. If you need any further help, don't hesitate to ask. We will all try to pool our combined knowledge to give you a hand, right boys? [MENTION=1172]Alin[/MENTION] [MENTION=9]HolyCrapItsFast[/MENTION] [MENTION=662]Batmobile_Engage[/MENTION]

[MENTION=662]Batmobile_Engage[/MENTION] if it were the clutch what other symptoms would it show because i got receipts showin they bought a new clutch and i do not want to buy a clutch when the clutch is fine you know?

izeahhh40 said:

@Batmobile_Engage if it were the clutch what other symptoms would it show because i got receipts showin they bought a new clutch and i do not want to buy a clutch when the clutch is fine you know?

Click to expand...

If the clutch is replaced, but the flywheel isn't either replaced or resurfaced along with the clutch replacement, that can cause it to slip.

[MENTION=1172]Alin[/MENTION] it has 156,xxx miles and the only thing it has is a 3" piping exhaust, from what i can tell. The previous owner said they redid the fuelinjectors and the pistons and they replaced a lot of gaskets.

izeahhh40 said:

[MENTION=1172]Alin[/MENTION] it has 156,xxx miles and the only thing it has is a 3" piping exhaust, from what i can tell. The previous owner said they redid the fuelinjectors and the pistons and they replaced a lot of gaskets.

Click to expand...

What about the timing belt?!

If it's the clutch, it isn't going to last much longer. Once they start slipping that bad at high revs, it's usually only a few days before it starts slipping at very light throttle, at which point you will have a hard time starting from a dead stop. Sometimes people hear clutch noise, though I never have and sometimes you can smell it....if you know what burnt clutch smells like.
Do you shift down much? If you are still driving the car everyday, I'm hesistant to tell you to try things to figure it out because you could find yourself stranded. Either way, like Alin said, it's best not to drive the car hard until we figure this out. With that being said, you could shift down around 40-50 mph and see if the revs jump up without actually slowing you down much. This would be a way to get some clutch feedback without boosting into high revs.

TK-421 said:

If the clutch is replaced, but the flywheel isn't either replaced or resurfaced along with the clutch replacement, that can cause it to slip.

Click to expand...

When you replace the clutch, the flywheel is often resurfaced. Do yourself a favor and buy a new flywheel everytime you replace the clutch. Resurfacing the flywheel doesn't necessarily make it weak as some will tell you, but it does often make it thin enough that hot spots develop on the flywheel causing it to weld your clutch to your flywheel.
(This is not during normal driving, but hard launches and high rpm gear changes can do this.)

Sadly, I have first hand experience with this happening.

[MENTION=4577]TK-421[/MENTION] I am going to get that boost leak test done and i would like to know how to get data logging and thank you for your help i appreciate it. Wouldnt my gears grind or pop out if it were the clutch? When i turn on the ar and step on it after hitting probably 4500 rpms it begins to like studder it like rocks back and fourth its pretty weird. Idk if you've ever heard of this situation?

[MENTION=1172]Alin[/MENTION] i honestly dont know since i barely got it last week from a guy that did not know anything about cars. He gave me the receipts of everything the previous owner had bought it

How knowledgable is your uncle since he is literally there with you?

Also did you have a compression and leakdown test done prior to buying the car?

[MENTION=662]Batmobile_Engage[/MENTION] so i have to resurface or replace the flywheel and the clutch but idk if you understood like what is going on with my vehicle hopefully it is that and i mentioned it to [MENTION=4577]TK-421[/MENTION] that when my car hits 4500rpms it begins to rock back and fourth and wont speed up like if it were studdering. Idk if that can help pinpoint the problem?

[MENTION=1172]Alin[/MENTION] he has been a mechanic for about 10 years but he is not familiar with subarus and no i have not done that.

Ok drive the car like a grandma if you have to drive it. If you can drive something else then leave the subaru alone and dont drive it. Depends on your situation.

Wait for the guys to respond and we can go from there cause we wouldnt want you to damage anything in the time being.