Headers, catted y, cat back... Popping? Missing?
This is a discussion on Headers, catted y, cat back... Popping? Missing? within the External Engine forums, part of the LSx Technical Help Section category; Hey guys, Christmastime, I had a set of Kooks emissions long tube headers, catted y, Magnaflow cat back, NGK TR55 ...
01-21-2016, 03:20 PM #1
Headers, catted y, cat back... Popping? Missing?
Christmastime, I had a set of Kooks emissions long tube headers, catted y, Magnaflow cat back, NGK TR55 plugs and Corvette style front 02's. When I am driving under light load in 5th and 6th (at 45-65 mph 1-1.5k rpm or so) and I try to accelerate past 1/3 throttle or greater, it feels like the engine is missing. Today, I decided to get-into-it a bit, so I was doing full throttle, and it started popping-missing above 5k or so. The car feels really good at 1/3-1/2 at 2-3k rpm though and I really havent suffered gas milage wise and no codes, the only real changes programmed into the tune is to give the 02s more time to heat up before throwing a code. This all happens when the cars at proper operating temps.
Everywhere that I have read, with a full exhaust upgrade, a tune is beneficial but not mandatory. Is my car just more sensetive than most? I would thinks the way its acting, I'd almost think the TPS was off, but I'd figure a code would be thrown though.
Last edited by Whamhammer; 01-21-2016 at 03:47 PM.
01-21-2016, 05:34 PM #2
Sounds like a not so happy coil pack.2000 Trans Am WS.6 M6
SLP lid & bellow w/ K&N, GMMG catback w/ Corsa Clones, UMI SFC, UMI Adj. Panhard, Eibach prokit, Bilstein HDs, Nitto NT555s, skip shift elim, whiteface overlays, 20% tint, matte black decal/overlays
01-21-2016, 05:37 PM #3
01-22-2016, 03:28 AM #4
- Join Date
- Feb 2009
- Mansfield, PA
Black & Blue
- '02 WS.6 / '07 Suburban
Go back over your ignition wiring. Remove and reinstall all the plug wires and ensure that you can hear/feel one "click" at each plug and two "clicks" at each coil pack. It does sound like a misfire -- under load the spark plug requires more juice to light off the air/fuel mixture in the combustion chamber and a bad connection could be the culprit. Misfire detection is based upon a sensor that can detect each the "push" each cylinder gives the crankshaft when it combusts. Could be that it is enough to be noticeable, but for some reason is not being picked up by the PCM to trigger the SES. Other potential issues would be fueling, a vacuum leak, or a MAF that is acting up. To test the MAF simply unplug it and take the car for a ride. This will force the PCM into speed density mode. The test will also trigger the SES so you will need to clear the code after the fact.
01-22-2016, 04:01 AM #5
My guess is if it just started right after the header install it's likely something to do with that; such as a loose plug wire. Might want to make sure while you're looking things over that no wires are close to the headers.It's stock.
01-22-2016, 11:28 AM #6
Hopefully its something fairly simple, stuff happens, I just which it would have thrown a code to make it easier to find the "stuff".
01-22-2016, 05:17 PM #7
01-23-2016, 03:59 AM #8
My speed shop did the full exhaust/plugs install, so I cant say if they used dielectric grease.
A few weeks ago, I did go back to the shop because I was hoping they could increase the clearance between the y pipe and the ground ( it was as good as it got), and thats when I had him check the low end, top gear acceleration missing, in which he rode with me with his computer and saw that the knock sensor was picking up some mild knocking but he believed some of it was because I was bogging the engine (trying to accerate in sixth at 1-1.k rpm.) and that the full exhaust moved the torque band/curve up and made the bogging more noticable than before, which made some sense to me.
I never experienced the full throttle problem because I have had snow tires on since the install and drive more conservatively than usual on these tires.
Of course, theres about two feet or so of snow surrounding my car, and still snowing, so I cant mess with it yet. Can someone tell my company approvea massive pay raise for me, so I can buy a house with a (heated) garage?
01-25-2016, 09:20 PM #9
first thing I would do is take it back and let them figure out what they did wrong....definitely something on the install side isn't right. Could be a few things really. I wouldn't rule out a fueling issue from an exhaust leak or something like that either. Almost sounds like it's doing it when it goes into PE. Do you have anything to log it with and see what your fuel trims look like? Like I say though....I would start with the installers.
01-26-2016, 03:04 PM #10
01-28-2016, 09:10 AM #11
Coolant temperature sensor is probably broken or not connected, been there done that. Right after a header install matter of fact. Never threw a code but ran like ass and backfired a lot WOT.
01-28-2016, 03:06 PM #12
01-28-2016, 05:12 PM #13
I am very happy I chose this shop, I called him on the phone and told him about the problem, he made the time for me and knocked the whole thing out in no-time. Lets face it guys, most shops these days would want to set up an appointment first.
01-28-2016, 10:33 PM #14
01-29-2016, 05:01 AM #15
03-03-2016, 04:25 PM #16
Glad you got it figured out! Very decent shop.
Users Browsing this Thread
There are currently 1 users browsing this thread. (0 members and 1 guests)
Question: Need headers and catted YBy Goldcuffs in forum External EngineReplies: 2Last Post: 07-24-2011, 01:46 PM
Question: SLP headers&catted y pipe kitBy MudStainKILLA in forum Firebird / WS6Replies: 12Last Post: 06-09-2011, 06:18 PM
By 30thcamaroz28 in forum General HelpReplies: 0Last Post: 05-09-2007, 11:27 AM
By Chubs in forum Suspension and HandlingReplies: 8Last Post: 03-27-2007, 08:13 AM
By Bad30th in forum Western MembersReplies: 0Last Post: 02-14-2006, 10:02 AM