B6 S4 diagnosis

B6/7 S4/RS4
#1

Just was trying to help someone out with their b6 s4. It has jhm 91 tune, piggies, and sebring muffler. Isn’t tripping a CEL but he said it seems to lose power when going up a hill and he has to really gun it to get it going again. And sometimes he hears an odd ticking noise from the engine when this happens. Wasn’t impressed with the tune because he said all he feels is like the throttle is jumpier.

I had him take me around the block and do a few pulls. It didn’t exhibit any weird behavior but it didn’t feel right… I’ve been in a b6 s4 with tune and fullback exhaust, that felt quite fast, pushes you back in your seat nicely. This felt around the same speed as my GLI, maybe even slower. I almost wonder if whoever did his piggies didn’t actually do them.

I know it’s vague. But does it ring any bells? What should I log for him to troubleshoot?

#2

If they left chunks of cat material in the down pipes his main cats could be plugged, essentially choking the engine.

#3

I got tuned on my b7 and felt like I wasn’t much quicker…almost that I had lost torque. Until I tested the car. The difference was huge. It was a mindfuck. I had a gtech and doing 0 to 60, 0 to 100 and 1/4 mile testing all show3d that I picked up loads of acceleration.

The tune removes some artificial restrictions. When you lose those, you lose a bit of a hit that used to make you feel power come on. Now its just always there. Similar to the rs4 throttle restriction. When guys get a tune and lose that 5500 hit they sometim3s tgink they have carbon buildup and have lost the kick. No, you juat made the kick fun from 1 rpm to 8250 instead of 5500 to 8250.

You have a more steady, continual delivery of power.

#4

He sounds like a tool. Talk him into getting a proper catback. How is this kid on maintenance? Coils/plugs. Does he have anything stupid on the car like a hot air intake?

My situation was a tad different, but after my full exhaust and tune my car was a beast. Before the install my wife said, “how much can an exhaust and tune really do?” Well I let her take it out after I got done and I believe she scared herself, it was a “holy shit” followed by a huge smile.

If he complains about the touchy throttle, tell him to learn how to drive and stop being a bitch. That is the most annoying complaint I see. All that means is you probably couldn’t drive the car correctly BEFORE and the tune just made it obvious.

#5

Jake, that makes sense especially from how he described his piggies install (left it with some guy not sure if he actually did it or not lol). Would that not trigger a cel though?

Haha not a tool, the car is pretty well kept engine-wise. He wasn’t complaining about the throttle, that was just the only thing he felt was different after the tune. I’ve been in 2 other jhm tuned s4s (one with catless FI, one with catted/res FI) both felt significantly faster. Those cars would bend my little jetta over without even paying for dinner, whereas this one felt about the same speed-wise.

I’ve recommended a shop for him to go to. I’ll reach out to them and see if they can check if the piggies were actually done, or done properly.

A fun and free alternative would be to do some pulls against a jhm tuned s4 with a full FI exhaust.

#6

Check the intake flap. For a while mine was stuck in between positions and the car was a dog until I fixed it. Didn’t throw a CEL either.

#7

Good point, a flap stuck in either direction can cause a severe loss in power.

#8

Intake flap arm video
http://audirevolution.net/videos/115/intake-flap-activation

You actually don’t even need to rev the motor. Have someone pop the hood and turn the key to acc with the car off, the vacuum system should pull the flap into the number 1 position.

#9

Thanks Jake and CV. I’ll try to meet up with him tomorrow and check the intake flap, then go from there.

#10

Good luck, definitely make sure he doesn’t have issues.

Just let him know that a retrictive catback is giong to take away a lot. It’s good that he has piggies, but his mufflers are basically a sound only mod. Show him a picture or make him lay under the car and point out how bad the piping pancakes going around the rear diff, he won’t be happy until he opens that thing up.