shuddering at 1/2 to 3/4 to wot when accelerating at highway speeds with cobb

[timo1980]

As the title says, I have shuddering at partial throttle at highway speeds. I think it's boost oscillations. How can I fix this? I am thinking of going back to using the procede, since it never had these problems, and boost was perfect. Is there a fix for the accessport? I see lots of people with these problems, why hasn't cobb fixed them? I am running the drive maps with ACN 91 gas. Please help, this is driving me crazy.

[Venom]

I was under the impression that the boost oscillations were fixed with the new maps. try updating to the latest release. if that doesn't work call cobb support or pm robb@cobb

[timo1980]

I am running the latest maps, but I am using the drive map, which is at 4.01, the sport and aggressive, are v4.02 which supposedly has the fix. I'll try pm-ing rob, but I'm pretty sure that I'm not the only one with this problem.

[Venom]

This site has been finicky lately, I replied but it didn't go through ...
Anyways:
I am running the same map as you Stage 2 Drive and have 0 boost oscillations, the power comes on through and true, my only little issue is that this map seems to bog a bit under 2k rpm and under 0 load my exhaust at the same 2k rpm sounds like fireworks (reminiscent of the misfire/antilag system).

[Venom]

Also shuddering might also be a symptom of another issue rather than the tuned map: it could be a bad coil/injector/hpfp. My last HPFP gave symptoms before my car lit up warnings on the dash.

[John Dempsey]

read your codes, and why did you switch to the cobb.

[Stohlen]

Originally Posted by timo1980

I am running the latest maps, but I am using the drive map, which is at 4.01, the sport and aggressive, are v4.02 which supposedly has the fix. I'll try pm-ing rob, but I'm pretty sure that I'm not the only one with this problem.

I used to have this problem occationally on my Subaru Legacy. It just was so occational that I never cared to fix it on the car as it was just a daily.

[Freon]

Shuddering is misfire or knock (or the ECU's reaction to knock and cutting power).

I had similar issues, haven't had time to truly work out and eliminate them. I will remark I had no issue until I went into service and had my HPFP and three injectors replaced under precaution/TSB, and a factory ECU reflash. I had the dealer check it out and they pulled a misfire code and updated me to IJEOS from IJDOS revision, but were unable to reproduce (I uninstalled my Cobb before taking it in). It was bad enough once to put my car into limp mode briefly, and it seemed like one cylinder was just straight up disabled, and it ran like it was out of balance.

Wish I had more to add for now. Not sure if it is a Cobb issue. If after replacing my plugs and maybe taking a look at my intake valves for carbon build up and not finding any issues I'm considering buying a JB and seeing if it can run elevated power without misfiring.

I have no issues with the factory ECU flash or the "Drive" Cobb tune (almost no extra power). On the "medium" or "aggressive" maps the car often misfires at peak torque and peak boost, 3000-4200rpm or so.

[ragingpanda]

I used to have a similar problem until I replaced my spark plugs. I am very certain it is hardware related and not the tune itself.

[loesch]

I have the same issue with JB4 on N55. Feels like a vibration at low RPMs. If I switch to a stock map it's completely gone. I too haven't had the time to work it out. Just running stock map most of the time. It's cold as hell so I'm not driving it much anyway. I'm probably just going to see what updates come out over the winter months and troubleshoot it in the spring.

[Spoolin Montego]

I have this same issue with cobb on stage 2+ sport. If i load the gear I get flat spots at certain rpms.

[Freon]

I will also add Cobb has a troubleshooting video too that seems to address this, and they go over changing plugs, coilpacks, and injectors. I'll give them the benefit of the doubt until I really go through the troubleshooting steps they've offered up. Just been to busy lately...

I'd strongly suggest everyone watch this: