UPDATE...I think I am missing a bolt on the left side of my downpipe (driverside) looking from underneath the car. I just have a hole there and from pix I have seen of the downpipe installed this hole is closed up with a nut. Can anyone please confirm this and if this could be the cause of my car throwing a lean code and the loud rattling?! I posted a pic of another person with the AMS DP installed with the nut in place and a few pix of my car with the DP and CAT installed with the hole and no nut over it on the DP in posts below. Please take a look.

THANKS!


I just recently had the AMS Widemouth Downpipe installed with an AMS High flow cat and got retuned. I also had a DW Fuel Pump installed. Since I have the Borla Cat back which is 2.75 inch in diameter and the AMS being 3 inch I got a small rattle from the 1/4 inch leak after install, but this isn't the problem.

Its been a week since the install and tune and all of a sudden while driving today I hear a very loud rattle and it kicks in around 2000 rpm and just gets worse as I get on the throttle more. I also started throwing the P0171 (System too lean) code!

The rattle sounds like its coming from underneath the front passenger compartment and dash so either around the DP or CAT.

Could it be that one of my DP bolts broke, or the Exhaust gasket warping from the original leak causing a bigger leak between the CAT to my cat back? Or is it maybe my fuel pump not being installed correctly thats causing me to get the code and weird rattle?

I got everything installed and Tuned at Akuma Motorsports.

PLEASE HELP! I feel like it's dangerous to be driving around like this.

 

Check the High Flow Cat on the side closest to the driveshaft. I had a similar issue (without the engine light). Where the AMS Midpipe was bumping into a stud which held on a heat shield around the driveshaft.

As for the engine light, Check your 02 sensors and get the exhaust leak fixed. Check the downpipe for looseness when the vehicle has cooled down to see if it is loose at all. If you have a leak before the 02 sensors that could cause you to throw a code. If nothing is wrong with the exhaust and the vehicle is running abnormally AT ALL, I would strongly recommend taking it back to your tuner to ensure there is no problem with the tune.

 

Okay and if its bumping into the stud how should I go about solving that? My rear O2 is disabled since I have the AP and I dont know how to check my first one?? And about getting the leak fixed, How can I get that fixed my tuner said since the AMS midpipe is 3 inches and my catback is 2.75 I will always have that quarter inch gap unless I make a custom merge pipe by cutting my catback and welding it to the midpipe. I will try to check if my DP is loose when its cold.

 

With my situation I was able to cut a small portion of the stud off and was still able to retain use of the nut and heatshield. Use a cutaway tool and be careful not to mar the threads of the stud. Just check the 02 sensor to make sure it is plugged into your exhaust. I may be mistaken but I think you may be able to use a couple exhaust gaskets to close up that gap. If not then your best choice would be to weld it, however, this entails work down the road should you need to replace your midpipe.

 

I will talk to my tuner tomorrow and see if he can figure out whats causing the rattle and P0171 lean code. If the problem is the stud in contact with the midpipe than I'll have him cut a part of it off like you said. I'll also have him check the 02 sensor and ask him about plugging up the leak with a few gaskets. I would like to be able to switch to my stock cat on my aftermarket catback in case of trouble with emissions so I don't really like the welding option.

Also if a downpipe bolt did break would that possibly cause a rattle?

 

The downpipe has 4 bolts and a stud to lock it in, so if one were to break I still don't think it would cause a rattle.

 

JUST GOT UNDERNEATH THE CAR AND THERE IS A HOLE ON THE LEFT SIDE OF THE DOWNPIPE (DRIVERSIDE) Is this where the 02 Sensor would plug into???? Because if it is than its not there anymore and its just a hole now!

Would the O2 sensor not being plugged into the downpipe cause a rattle and a P0171 System Lean code?!
I can't see the O2 sensor wire anywhere either like shouldn't it be hanging right there if it somehow got disconnected?

 

UPDATE...I think a bolt is supposed to close that hole up according to a few pix I have seen of the downpipe installed. I guess I'm missing that bolt...it must have been loose.

Can anyone please confirm that this might be the cause of my rattle and throwing code problem?!

The bolt in the pic shown is the one I'm missing. I just have an open hole there!

 

Yur gonna wanna close up that there hole. Either with a plug or a bolt or sum cauk. Jus sayin....

 

Okay so good to know thats not normal...Could that be causing my issues?

 

Here are some pix of my Downpipe. You can clearly see the hole that I think should be plugged.

 

The best thing would be to come to the shop. If the bung plug fell out we will happily give u a new one. I am in the hospital right now...baby on the way...so I can not look the tine over until Thursday. Always call us first and we will always take care of you.

John

 

Thank you very much! I was going to call you, but I barely realized this evening after you guys had closed, but since you saw this quickly and responded I feel much less worried. You guys are great! Congratulations by the way and no problem I understand, I wasn't planning to make a trip until Thursday anyway. I will call tomorrow to confirm that I will drop by Thursday to get this issue resolved.

Thanks again!

 

Yup needs a plug doubt caulk would work

 

Caulk? Uhhhh no. A bolt? Maybe, but I suggest a bung plug welded in. Do it right.