[Leesin]

Today after I installed the stage 1 aggressive map on my 335i my car felt fine, but after I put some down on the pedal at around 5k rpms the car immediately "lost power" and started shaking crazily. Also the check engine light came on. I checked in the troubleshooting of the cobb and it said there was a misfire in cyl 6 and an HPFP failure. I then reverted the car back to stock and drove it around and it felt fine (even at ~5k rmps). So my question is, is it normal that the car misfires with stage 1 aggressive map but then drives completely fine when put back on stock settings? Also there isn't any check engine lights on after reverting to stock settings.
I think it is worth mentioning after installing the map the initial time, a traction control light came on (stating not to brake hard).

[JStang]

When did you last change your spark plugs? You need to change plugs about every 20k miles when running a tune. Could also be an ignition coil. Both are easy fixes.

[BQTuning]

Sound like a bad spark plug or coil. A bad spark plug or coil will show it face when more power is being added.

[Eat.Sleep.Race]

I replaced spark plugs and coils before installing a tune, no issues, but if your fuel pump is going bad, def get that replaced.

[Seymour Boost]

I'm assuming the fuel pump code is the plausibility one, which is nothing to be concerned about.

I had a misfire immediately after installing the Stg 1 Agg map as well. It was resolved with a new coil and I did the plugs while I was in there. No biggie.

[Leesin]

Thanks everyone for the immediate replies. Come to think about it the cobb troubleshooting said Misfire from spark plugs. So definitely need to change those. What about HPFP, how much would that cost to repair?

[Leesin]

Originally Posted by Seymour Boost

I'm assuming the fuel pump code is the plausibility one, which is nothing to be concerned about.

I had a misfire immediately after installing the Stg 1 Agg map as well. It was resolved with a new coil and I did the plugs while I was in there. No biggie.

Glad it worked out. But after the misfire did u uninstall the cobb and run the car on factory settings? How did it drive?

[JStang]

Originally Posted by Leesin

Thanks everyone for the immediate replies. Come to think about it the cobb troubleshooting said Misfire from spark plugs. So definitely need to change those. What about HPFP, how much would that cost to repair?

Just do plugs first. They take care of 90% of first time tuner misfires.

[Seymour Boost]

Originally Posted by Leesin

Glad it worked out. But after the misfire did u uninstall the cobb and run the car on factory settings? How did it drive?

No, I left the cobb installed and changed the coil/plugs.

[BQTuning]

Originally Posted by Leesin

Thanks everyone for the immediate replies. Come to think about it the cobb troubleshooting said Misfire from spark plugs. So definitely need to change those. What about HPFP, how much would that cost to repair?

Sometimes when a misfire occures caused by a bad coil or plug it will also trigger a plausable fuel pump code. It does not mean your HPFP or LPFP is going bad.

You will experience sometimes, and alot of times when an error occures it can cause a domino affect. It doesnt mean all hell is breaking loose

You first have to diagnose the issue. Swap coils around to see if the misfire will follow. If it does then it is a coil going bad

If the misfire occures in the same cylinder then change the plugs.

[Digitalism]

Originally Posted by Leesin

So my question is, is it normal that the car misfires with stage 1 aggressive map but then drives completely fine when put back on stock settings? Also there isn't any check engine lights on after reverting to stock settings.
I think it is worth mentioning after installing the map the initial time, a traction control light came on (stating not to brake hard).

Running stock boost/load isn't going to be as hard on the engine and its components as it is running a higher boost/load.

The aggressive map is going to show weaknesses in the engine ie plugs, coils, injectors or fuel.

Did you log with the traction control off?

[Leesin]

Originally Posted by Digitalism

Did you log with the traction control off?

Sorry I don't understand what you mean

[Jeff@TopGearSolutions]

Originally Posted by Leesin

Sorry I don't understand what you mean

If you have to ask it was likely left on.

It's the DTC button. It's traction and stability control.

If left on it can intervene and skew results of datalogs.

Hold the button for 5 seconds to turn it off.

[Leesin]

Originally Posted by Jeff@TopGearSolutions

If you have to ask it was likely left on.

It's the DTC button. It's traction and stability control.

If left on it can intervene and skew results of datalogs.

Hold the button for 5 seconds to turn it off.

datalogs/logging is basically checking for codes on the a/p, correct?

[Jeff@TopGearSolutions]

Originally Posted by Leesin

datalogs/logging is basically checking for codes on the a/p, correct?

That would be incorrect. Codes are just stored malfunctions.

A datalog is when you set up the tune to record all the sensors (most of the important ones) that tell you how your car is responding to the added power.

Things like RPM, Boost, Air Fuel, Ignition Timing, Intake air temps, fuel trims are all monitored. That information can that be utilized to see if your car is taking the added power correctly and or if adjustments need to be made. Datalogs will tell you if the tune you are using is too aggressive or if you may be leaving some power on the table.

Most Cobb maps are conservative for most vehicles but it's always good to double check them as other exterior conditions can factor in.

Datalogs are typically a 3rd gear pull, wide open throttle the entire time from about 2500 RPM to Redline. (In a safe area).

2nd gear is typically traction limited and not enough engine load or heat.

That is why logs should be done in 3rd gear.

4th gear would be ideal but too unsafe and impractical for normal street datalogs.

[vivanapoli806]

Just dish out the $95 for new plugs and be done with it. Same happened to me when I got cobb tune. If it still happens it's a coil

[Jeff@TopGearSolutions]

Originally Posted by vivanapoli806

Just dish out the $95 for new plugs and be done with it. Same happened to me when I got cobb tune. If it still happens it's a coil

Yes, it's very likely he needs new spark plugs because they need to be replaced every 25,000 miles anyway.

We actually put in our Cobb listing to change spark plugs because so many people tune without changing spark plugs and as a result end up misfiring.

http://www.e90post.com/forums/showthread.php?t=631829