: 02 SLS running rough after pulling air box silencer

07-06-08, 02:13 PM
I screwed something up...I popped off the silencer by accident when trying to check my transmission fluid while the car was warming up for the first time today. The car was running at the time when it popped off, and then the car stalled out when it came off. So i just left the car off for a few minutes and then put the air box silencer back on and started the car up again and it seemed fine.

Went out to the stores and got on the gas getting onto the highway at one point and around 4500-5k the car started bogging out and i slowed down and drove it normal for a bit. then i figured i check it again to see if it will still bog out, and it does.

Well now that i got it home in my driveway. the car ran fine idling for like 2 minutes hot and then all of a sudden the car idled way down below 500 rpms and i tried giving it alittle gas and the car now sounds like it's running on half the cylinders!!!

I checked the codes on the car the first time it had all history codes nothing regarding the PCM. So i decided to disconnect the negative on the battery and wait like 10 minutes. Now i put the neg cable back on and proceeded to start the car. It started fine for a minute then started that rough idle.

So i shut the car off again and check the codes one more time. NOW i have a P1359 code which refers to a Ign Coil problem???

I don't know what else to check...I need some help folks.



07-06-08, 02:23 PM
Hopefully the ignition coil code is just a hiccup....the car won't run well at all with even a slight leak past the MAF.

Did you get the resonator fully seated in the intake pipe ? That permanent clamp can be a bear to get correct......try a smear of grease around the resonator spigot, or, better yet, try the below pic with a 2" hardware store pipe cap. Comes with the clamp..............sure does make transmission fluid checks and air filter changes easier..........scroll in......find a suitable screw for the air filter box top. I had the spring clamp on there while I was adding 2 stsm screws to the corners of the air box top......

07-06-08, 02:32 PM
so putting that pipe cap in won't f'up the MAF?

And i got the car running again, i just let it cool down and left the battery off the entire time since last. Car started up fine, ran good, no PCM codes.

Now i can leave to go where i need to go.

ON EDIT: Car still has the bogging down/ hesistation issue when getting on it!!!!!!!!!

I can drive the car like normal but still it probably isn't good having this problem up high in the rpms.....

Car drove like a champ yesterday and i was making good use of the engine last night....

07-06-08, 03:08 PM
Nope, won't bother a thing....documented in here and N* Performance as "butt plug", last year.

Get the plug and pull the MAF/intake pipe off. Make sure the MAF is seated in the proper orientation in the rubber collar adapter to the air box. Temporarily stick the plug, skirt down, in the air pipe. Look in both ends and mark the skirt of the plug with magic marker/Sharpie, pull the plug and trim the skirt so it doesn't hang down quite so far into the airstream. The clamp should be snug, not tight.........Orient the MAF so the airfoil flow straightener is more or less horizontal and the plug doesn't interfere with the transmission dipstick. (That's not a screen on the MAF: it's a 1/4" thick honeycomb flow straightener, just like in the wind tunnel pics in car ads.)

07-07-08, 08:38 PM
ok well my car died today coming home from work.

Engine started chuggin and then the SES light flashed on and off. I managed to get it home as it happened a few blocks from my house. After getting it home i checked the Codes and got a P0300 Misfire detacted. Now i had the car towed to the shop and i was curious as to how they can find out what broke on my engine. I bet it's the Ignition Module on one of the engine banks. I will find out tomorrow hoepfully.

Are the ignition modules grounded somewhere on the car?????

07-11-08, 03:36 PM
Sounds like a coil(s) crapped out. SES light flashing means "Catalyst damaging misfire" Car was throwing raw fuel through the cat due to no spark. I would bet you've got either 1 or more bad coils. Strange coinsidence that it would fail after you removed the silencer, but they go when they want.

edit: Whichever coil it is it's probably weak and unable to keep up with demand, and when it's pushed it simply fails. Could be a very small break in the coil winding going open when it gets too hot.

07-11-08, 05:21 PM
It's an '02. Have the CKP sensors ever been changed. If not, That most likely is your problem.

07-13-08, 10:07 AM
Yup the Sensors were change last year, i got the car fixed, it was the Ignition Module for the front cyls. Car runs great now.

Thanks for any help.

07-13-08, 06:32 PM
90devilleguy..........Did you change the whole 4-coil cassette or just the ICM that plugs into the end ?? What kind of shape were the plug boots in ??

What narrowed your diagnosis down to the coil(s) ??

This is great archive info........someone will come along and learn from this thread, and all the info would be helpful.