CEL and no acceleration
 

I finally got the car tuned on EcuTek and with RaceRom feature and on my way back the check engine light came up but the car was still running fine. I even tried the car and it was quick and fast for the short time I was able to drive it without having the loss of acceleration. Then a couple days later the CEL is still there but it was flashing during acceleration and at that point I had no power. The idle is fine and it does not sound abnormal. The spark plugs were changed by the tuning shop. I have an appointment to the dealership to have the oil changed and check the codes. What should I try by myself to solve this in the meantime?

If you have the ecutek dongle, I'd do some logs and send them to your tuner. Sounds like a tune issue

Who tuned it?

Total Tuning located in Quebec

Here are the codes. The dealership erased them, the light did not come back on but it still runs like it's in limp mode.

https://www.ibb.co/LrJbkdw

Should I disconnect the battery?

Worth a try. The ECM will lose some tuning data and you'll have to drive around for a while until it relearns. You may have to do a window reset and the presets on the radio again.

Will this procedure remove my tune per say? Will I have to do a throttle body relearn or something else? As for the tuning data, what are you refering to exactly? Should I drive the car hard to have it learn to be quick? lol

You won't lose your Ecutek tune and there's no reason you would have to do a throttle body relearn. And.no, you shouldn't drive it hard. Why aren't you talking to your tuner about your situation?

Understood. I will go ahead and unplug the battery for a day or two. I am reaching out everywhere and to anybody right now and I'm looking for support and guidance. Unfortunately the tuner appears to be unavailable.

I've had glitches in a tune one time. I reflashed it and everything was fine

Usually these problems can be remedied by the tuner especially if they arised after the tune.

Disconnecting the battery should drain the car in 10 mins or less, no need to leave for a day or more.

I do not have the cable or the dongle. I called the dealership mechanic and he said the flashing was a misfire and it could be due to an air leak or bad connections more than likely. He asked about the P300 code and I told him I did not get that code meaning it should not be real knocking otherwise I would have had that code or if it stopped knocking the code may have gone away by itself. The dealership mechanic suggested verifying all connectors are indeed well plugged in. He said unplugging the battery will not remove limp mode if there is but it will erase codes but still worth a try.

Worth a try until you get a response from the tuner. The dongle and cable are a worthwhile investment

I just tried the car, still no dash lights. I cold driven the car and it seemed to have gained its power back but after maybe just a minute it got slow again.

Disconnect the battery. Step on the brake pedal. This will relieve any current in the electrical system that maybe present. Reconnect the battery. If you have an Ecutek or UpRev tune. Disconnecting the battery won't affect the tune. What will affect the tune is if the dealer reflashed the ECU with the tune still in it. Then the tune is toast. Sometimes removing the tune and then reinstalling it will help. If not, see your tuner.

Called the tuner and he said the problem is the o2 sensors. He would reflash the car to have EcuTek ignore the o2 sensor reading. He wants to charge me for that.

Sounds like a greedy tuner to me. Most of the good tuners would not have any problems making the quick change to turn off those sensors without additional cost.

I agree it's ******** to have to pay to fix something that should not have occurred in the first place.

Could another tuner use data logging and the current tune to send me a flawless tune through email?

You'd have to send them your tune and hopefully your tuner didn't lock his tune. Are you on Facebook? Contact Eugene Turkov. Here's his phone number. (415) 830-4008 He'll answer until 10:00pm pst. He's in California

Then it won't be possible since he tuned the car on the dyno and flashed it there. Again, could another tuner use data logging on an already tuned for my current mods car to speed up the creation of another tune?

I added the name and phone number to a tuner in my above post. Give Eugene a call. If anyone can help you, he can.

Went to the dealership and the technician verified the harness and it's working. o2 sensor wiring is good too, but the problem may be the o2 sensors themselves (both of them). That or it could be a damaged ECU or a flawed tune. Remind you the tunner wanted to deactivate o2 sensor reading to bypass the issue. Could my problem really be two broken o2 sensors? The technician told me it's very unusual to have both o2 sensor break at the same time.

As for testing the car after the dealership appointment, on cold start temperature the power was back but as soon as the engine gained some temperature it got slow again. I also got the service engine light soon flashing for a brief moment when trying to get to max rpm in 4th gear. The light disappeared as soon as I let off throttle. The technician told me the computer does not read o2 sensor data when the engine is cold but will do once it gets warmer. I think I also got in limp mode because I could barely get to 3000 rpm at one point.

So do you guys think the problem really is the o2 sensors? Dealer will happily sell me OEM sensors but will not accept any return on electronic parts so I must be certain otherwise I'll be stuck with them.

I assume you didn't call the tuner I recommended in my above post?

I just contacted him on FB now. I wanted to have more troubleshooting done at first to eliminate common faults before contacting a tuner to help me figure it out even further.

The good thing about him is he'll help you troubleshoot

Another vote goes to faulty tune
 

Yes he does want to help me! I just talked to him and he thinks the problem is more than likely in the tune. He would check out my data logs and even send me a stock tune file. Thank you for recommending me Eugene Turkov, he really seems like a nice guy. I think I'm in good hands now.

Remove the tune and see if the problem is still there.

Do you have test pipes?

That's what Eugene suggested actually. I have high flow cats, catback and Z1 intakes.

The O2 sensor could have gotten damaged during the install of the cats. A lot of times, if a impact gun was used on the bolts before removing the sensors. The vibrations from the gun will kill the sensors. A lot of people on here have had that issue.

He is always willing to help. You are in good hands

Thing is my car was perfectly working before going to the tuning shop so I do not think the dealership did a wrong installation as I remember seeing him hand tight the sensors then use a wrench to torque it. Could o2 sensors break on a dyno due to heat or vibration transmitted to the car from the tow straps?

I don't think so. It would have to be a really lean, or really rich mixture to foul the sensors.

The tuner did 10 pulls before final flash could this be it. I remember first pull was pissing gas from the tail pipes.

If you had gasoline running out the pipes. The sensors could be coated with soot. If that's the case. You could try to remove them and use a spray cleaner on them.

Any time I hear about limp mode/loss of power problems, I have flashbacks. I was having limp mode problems a couple years ago. Car would go into limp randomly. Sometimes it would run fine for days and sometimes would happen three minutes after starting the car. The only thing that seemed to temporarily fix the problem was let it sit overnight, disconnect battery for awhile, or use an app to clear any CELs (sometimes there were some, sometimes there weren't). All options inconvenient. As before, it would go back into limp after un undetermined time for undetermined reasons. Of all the things it could have/should have been, and all the things I tinkered with or swapped, it turned out to be the throttle bodies. I took them off and they looked spotless, but I hit them with some throttle body cleaner anyways and put them back on and now years later haven't had the problem come back once. Can't say if it will help your problem, but a couple dollars for a can of cleaner and 10 minutes of work won't hurt anything.

Changed the o2 sensors, cleaned the throttle bodies, cleaned the MAF sensors, cleaned the air filters and it's still happening.

Everything in this thread I've read seems to point towards something in the tune being the issue :twocents:

That was suggested in the second post :tup:

The original tuner made things right and richened up the AFR. He also disabled secondary o2 sensors. Car is a bit less snappy but does not pull timing anymore.