Stage 1 Cobb, hesitation and stutter

[Chronuss]

Apologies if this is not in the correct place, please let me know.

 

 

After many moons, I was finally in a place to get a new V3 Cobb for my 2005 GT 5EAT. After much anticipation, I followed the steps and flashed the Stage 1 93 map. Took out it for a spin and was completely dismayed at the hesitation and stutter that was not there with the stock map. I have included a log for people smarter than me in the hopes someone could tell me what is causing it and what I can do to correct it. In the meantime, I uninstalled the AP so it would revert to the stock map again, and the stutter is gone.

 

 

If there are any data points that are preferred, I can gladly get those by reinstalling the AP and reflashing.

datalog2.csv

Edited February 22, 2022 by Chronuss

[whitexc]

Something isn't right here. Your car is 100% stock and in good running condition(sounds like it runs fine on the stock map)?

 

I would contact Cobb after verifying your new AP has latest updates (available through AP manager).

 

While it wasn't an impressive change in power my car seemed to run smoother on the OTS Stage 1 93 map and most say it is better for engine longevity than the stock map (I got 10k on the Stage 1 map and spun a bearing so.....).

 

Sent from my SM-G996U using Tapatalk

[Chronuss]

AP has the latest firmware, made sure of that as soon as I got it. Am I not supposed to put it in Sport mode anymore? Is that where the stutter is coming from? As soon as it went back to the stock map, the stutter went away.

[whitexc]

You should still have Sport mode as an option. Again, I would contact Cobb. It's new you said so they will help you get it squared away. Maybe you got a corrupt file[emoji2369].

 

Sent from my SM-G996U using Tapatalk

[Chronuss]

Called Cobb, sent them over the log. Dude basically said I need to get an e-tune or have someone tune the map that I got from them and that just blows my mind. Also suggested I try the stage 1 91 map to see if that makes any difference, so I will try that this afternoon and get another log. If that doesn't really help, then I'm just going to return the damn thing since for whatever reason a map that works normally for an '05 and won't work for this '05 makes no sense to me.

[m sprank]

That log is not helpful. Too many parameters and the wrong type of driving. I dont give Cobb too much credence. If you are local "enough" to me I can assist. Chances are you have a small mechanical correction to make and the OTS map will be fine. Could just be a vacuum leak, but I need to see a WOT 3rd gear pull with specific parameters logged (or drive the car myself).

[Chronuss]

That log is not helpful. Too many parameters and the wrong type of driving. I dont give Cobb too much credence. If you are local "enough" to me I can assist. Chances are you have a small mechanical correction to make and the OTS map will be fine. Could just be a vacuum leak, but I need to see a WOT 3rd gear pull with specific parameters logged (or drive the car myself).

 

 

 

 

You tell me what data points you want to see and I will accommodate. This log is from complete stop, leaving my development, getting on to the highway and making a loop back to the development. The stutter would happen when trying to go full tilt when it was in third gear, and the car would literally stutter and go "badump, badump, badump," then accelerate through it. I know I'm definitely local to you if you know where Citizen's Fire Hall is, that's where I am.

[Chronuss]

Tried the 91 map. The hesitation/stutter is even more noticeable. Cobb said the log looked normal, but I can 100% tell you my car did not run normally at all. Back to stock map it is.

 

 

Also attached is a log of the 91 map. At 21.596 I'm getting on the freeway merge ramp and start to accelerate.

 

 

The first stutter happens at around 24.045 when the RPM starts to bounce.

 

 

 

It powers through it eventually and I get to cruising speed for a bit then take the next off ramp to circle back around to back the other side of the freeway.

 

 

The next indication of the stutter happens at 202.649, back on a merge lane to accelerate to freeway speed and the RPMs bounce again 205.091. You can see as it accelerates through it it bounces three times each time it happens then goes on its merry way.

stage1 91~datalog3.csv

Edited February 22, 2022 by Chronuss

[whitexc]

Is there a common throttle position or rpm range that you are experiencing this?

 

Sent from my SM-G996U using Tapatalk

[Chronuss]

Seemed to only happen when trying to accelerate in third gear. From dead stop and through second was fine, only when trying to punch it in third.

[m sprank]

Sheeeet... Your in Charles Town. I live 5 minutes away off Flowing Springs. Flash back to the stock map and shoot me a PM. I can meet up, check for the normal culprits under the hood, flash the car, log a pull or two and figure this out for you.

[xt2005bonbon]

You're lucky Chronuss!

 

 

Keep us posted on your findings.

[Chronuss]

Welp, after some troubleshooting, found a vacuum leak and a coolant leak didn't even know I had. After all said it done, gonna get that stuff fixed, probably send the Cobb back cause my 30 days are almost up. The entire reason I got the Cobb was so I could flash and get rid of the CELs when the uppipe is replaced, but I think I may just swing the resistor mod for the time being just to get rid of the catted uppipe.

 

 

 

Huge shoutout to m sprank for taking the time outta his day and riding around in my poor wagon up and down the mountain.

[whitexc]

Glad you found some sort of culprit. Not sure how it doesn't affect the stock tune and only the Cobb OTS.

 

I guess it depends on your budget, plans and situation. I would keep the AP. They come in handy on a few levels and are also the gateway (one of them anyways) to tuning. You could get the car fixed up, rid of that factory UP (pay for shipping and have my stock catless UP) and have someone brew up a nice E tune for your stage 1 ride.

 

Sent from my SM-G996U using Tapatalk

[Chronuss]

Wellll...I ordered the Cobb and the uppipe at the same time, and my 30 days to be able to return it for a full refund are closing in. So, return Cobb, get refund, use refund for unforeseen repairs. I MIGHT be able to swing enough time, but it would be close, cause I can't get it in to the shop until Thursday. I would have to get it shipped out on March 14 to be able to get it back in time so I could get the full refund.

 

 

 

It would seem theres a small vacuum leak somewhere between the intake and fuel pressure regulator. Also a coolant leak under the manifold. So, get manifold off, repair hoses. While its in the shop, go ahead and get the uppipe replaced and throw the resistor in and be happy for a while that theres no more cat right before the snail.

[m sprank]

Post MAF, pre turbo leak most likely. Could not see it, but a smoke test would find it fast.

 

Immediately upon boost AFR shoots to 18 and never gets richer than 17. AFR holds steady at idle and cruise. Load and boost bring on the lean. Little knock, thankfully. But not safe to boost that lean.

 

Sorry for your troubles.

[Chronuss]

Post MAF, pre turbo leak most likely. Could not see it, but a smoke test would find it fast.

 

Immediately upon boost AFR shoots to 18 and never gets richer than 17. AFR holds steady at idle and cruise. Load and boost bring on the lean. Little knock, thankfully. But not safe to boost that lean.

 

Sorry for your troubles.

 

 

 

 

Bro, you saved me time and headache and I greatly appreciate you taking the time out of your day to ride around in my old ass wagon and then stand around BS for a while. Let me know if you need anything or when it gets warmer and you wanna take the little one fishing.

[Max Capacity]

Just saying the Cobb AP stage 1 tune is how the car should have come from the factory. I remember that when I first loaded Stage 1 back on Dec 8 2004 when it first came out.

 

You should talk with Mike and do what he tells you too. You have no idea how lucky you are to have him that close.

[Chronuss]

Just saying the Cobb AP stage 1 tune is how the car should have come from the factory. I remember that when I first loaded Stage 1 back on Dec 8 2004 when it first came out.

 

You should talk with Mike and do what he tells you too. You have no idea how lucky you are to have him that close.

 

 

Yep, car is goin' in the shop for the vacuum and coolant leaks and get the uppipe done. Guy I use has a super nice shop at his house and a lift and climate controlled, cause I'm getting too old and chunky to put things up on jack stands and its still cold as hell here in WV. If it all gets done before I need to ship the Cobb back, great, if not, I got my five pack of resistors from Amazon.

[Infosecdad]

If I remember right, you have to unmarry the Cobb AP before you ship it back and that will revert back to your stock tune. The only way to have an updated tune or to remove CELs is to keep the Cobb AP.

[Chronuss]

Its been unmarried since the other day and back to stock. If I have enough time once everything has been done, I'll try the stage 1 map again, if not, I'll go ahead and send it back and be happy the wagon is back up to snuff.

[Max Capacity]

You're only doing the up pipe not the down pipe too ?

 

The 3" catted Dp really wakes the car up and stage 2 Cobb is fine for most of us.

[m sprank]

Car was totaled and just hit the road again. Owners plan is to turn the car into the wifes DD. It is up to the owner if he wants to travel down the rabbit hole with this car or if he wants to enjoy it as is. It is not your "standard" modding experience. I think the owner was excited to drive his LGT again after the accident. I can appreciate the overall situation he is in and if he decides to leave the car "stock" I completely understand.

[Chronuss]

Pretty much. We got it used in 2013, it spun a bearing in 2016, engine replaced, a 2003 Sierra tried to park in my passenger seat by way of right front headlight in 2019. Had to replace hood, bumper cover, headlight, and passenger fender. It unfortunately sat for about seven or eight months before I could get it road worthy again and get a reconstructed title. Just got it back from paint and wanted the stage 1 map and the catless uppipe to make it a bit better to drive and not have to worry about the converter letting loose for whatever ungodly reason. Alas, some minor things to take care of first.

[Chronuss]

Wanted to give an update for anyone that was following and for people that helped. Seems that the air leak was either coming from the intercooler or the gasket between the throttle body and intake manifold.

 

 

So, grabbed a new(used) intercooler from ebay and did the bulletproof mod on it, also straightened all the fins. Rebuilt throttle body from ebay, and polished it with a dremmel and some compound. Didn't remove the butterfly because I was simply scared I would mess something up. Coolant leak was coming from the coolant crossover pipe. Underneath there are two O rings, and they both were shot. Also had to replace the the throttle body plug to the wiring harness and the coolant temp sensor plug. If anybody needs to replace a plug, definitely recommend iwireusa.com. So after waiting for 2.5 weeks for parts and gaskets from Subaru, was finally able to get everything over to the shop last Friday. While waiting on everything, my mechanic took the intake manifold and rehoned and straightened it. So now wait a little longer and build anticipation in the hopes that the wagon will run better than when it went in.