Evolved8

Ok so a total of about 3 times over the course of a year my cars check engine light has come on.misfire.....

1st senario the first time It happeded was around last November when I got it. I took it to Advanced auto pulled the codes and it was multiple cylinder misfire. Cleared the code fired it up problem solved. I decided to replace all the Plugs with one step colder NGKs.

2nd Senario same thing cleared the code came on about 2 months after I replaced the plugs, Restarted issue gone.

3rd Senario Tonight Cel came on the way home from work, Started to run rough, CEL flashed for a few times then went solid. Pulled over and scanned codes p3005 p3006 p3007 p3008..... Cleared Fired up and came right back on. Cleared again and ran for a minuite and came back on.

Whats going on here guys?...........

rlh23

I assume you meant the code was P0300, P0305-P0308? The same thing happened to me after I had my FF LT's installed. Originally I extended the sensors and couldnt get misfire CELs to stop. I then bought all new sensors and extended from the harness. Since then, the misfire codes have stopped, but I have a CEL for O2 heaters that stays on permanently. However, the car runs fine (knock on wood!!). I even got my car tuned w/ the CEL on and it still runs fine. I know this didn't answer your question, but I was very frustrated with those misfire CEL's; almost to the point of going back to my stock setup.

Do you have access to a STAR system? That can probably diagnose the issue...I just hate paying for it every time I need something diagnosed.

GT-ER

Are you sure you don't mean P0305, 0306, 0307, 0308?

Have you changed your wires?

Crank Position Sensor may also be the issue.

Jakpro1

I think I kinda defer to RLH above on this one. When I had something as simple as 2 wires crossed on one O2 sensor, the friggin car was going haywire with misfire CELs.

Just don't get why it's not constant?????

You driving in rain or wash her today? Just curious. Mine freaks and throws misfires then too.

rlh23

I talked to Chris (Floored Fab) and he did say MB computers are so sensitive that it will throw a code if you do cross a heater wire. If I remember correctly, evolved lengthened from the harness though, so his O2 sensors shouldnt be causing this.

Like I said, it would probably save you a lot of time and frustration to bite the bullet and let someone w/ STAR look at it.

Jakpro1

Snagged this from a 65 forum post

Worth double checking your gapping on the cyls in question throwing CELs. Not sure what the gapping is for the 55s....just thought that might be a angle.

Jakpro1

last one of the night and THIS is one I would really put some thought into. Clogged cat. Heard of this more than once.

This poor guy spent 4500$ to figure out it was clogged cat causing misfires. Least the cat was covered under warranty.

I forgot though. I have floored fab heads like you BUT 100 cel race cats. Aren't you cat-less?

If so DAYUM! I would have thought we might be onto something.

Here's the post from the other guy

turbo97se

Did you pull any of the plugs to see what the plugs look like? Were they fouled or anything? The plug can tell you a lot, a CEL code .. not a huge amount. could be fueling or fuel trim issue especially with headers and messing with O2s. Gap size may be a factor also. I tend to set mine a little smaller under increased boost. Some people say colder weather has an effect though I personally have not experienced this. Also talk to whoever tuned your car if they have any thoughts on the subject.

Evolved8

Yes codes were as you stated. And I have NO cels for heater etc with the FF LT headers. This just happens every once in a blue moon.

I did not change my wires...

It was Moist and raining whe this occured...

I have 2 200cel race cats.

I have not pulled the plugs, If it was a plug you would think it would be consistant. Not every once and a while and they are NEW plugs..

Evolved8

Anyone?

shardul

iTrader: (1)

is there any way you can connect the car to STAR most of the time it will give you some more info.

bnzuovr

In order check wires they maybe arching u can maybe check them by spraying them with a bottle of water and see if there is a spark outside of the wire, 2 it maybe a possable coil problem, and 3 which i hope it is not it could be maybe a bad cylinder i had a misfire issue with my car and it ended up being a faulty cylinder which required a engine overhall. I would check compression & pull your plug to see if there is any oil or any damage to the plug. Hope that helps and good luck.

novae500

sorry to hear this problem my friend had misfire codes left/right and in the end, it was bad gas that he got. He changed plugs, wires, coilpacks, CPS, and the mb mechanic he used put in some BG44k on empty tank and ran it for 20mins hard. Afterwards, no more CEL codes.

gsxrguy

check your fuel pressure

chawkins2001

Has anyone actually looked up to see what those codes mean? I have a booklet at the house but I am sure you can access coding online.

chawkins2001

Here you go:

http://www.obd-codes.com/p0300

http://www.obd-codes.com/p0305

http://www.obd-codes.com/p0308

I know that Pullejo had some CEL issues after he installed the Floored Fab Longtubes, send him a pm as he got it sorted out. He also has a Eurocharged tune so maybe Jerry adjusted the some mapping.

novae500

P0305 Cylinder 5 Misfire Detected
P0306 Cylinder 6 Misfire Detected
P0307 Cylinder 7 Misfire Detected
P0308 Cylinder 8 Misfire Detected

A code P0305 may mean that one or more of the following has happened:

• Faulty spark plug or wire
• Faulty coil (pack)
• Faulty oxygen sensor(s)
• Faulty fuel injector
• Burned exhaust valve
• Faulty catalytic converter(s)
• Running out of fuel
• Poor compression
• Defective computer

Possible Solutions

If there are no symptoms, the simplest thing to do is to reset the code and see if it comes back.
If there are symptoms such as the engine is stumbling or hesitating, check all wiring and connectors that lead to the cylinders (i.e. spark plugs). Depending on how long the ignition components have been in the car, it may be a good idea to replace them as part of your regular maintenance schedule. I would suggest spark plugs, spark plug wires, distributor cap, and rotor (if applicable). Otherwise, check the coils (a.k.a. coil packs). In some cases, the catalytic converter has gone bad. If you smell rotten eggs in the exhaust, your cat converter needs to be replaced. I've also heard in other cases the problems were faulty fuel injectors.

Evolved8

I will be hooking a STAR system up to it on Monday. Does anyone else have real life experience on this issue?

rlh23

Seems like several people that installed FF LT's have had misfire CELs. I changed my plugs as well and that didn't fix it. I've spent ~$1000 diagnosing the problem, changing the plugs, labor, etc. and I still have the heater CEL on. I constatnly look at the solid CEL and wait for it to start blinking again.

Evolved8

My car did this a few times before the FF LTs were installed.

Jakpro1

Now that we are all getting together and talking, I think you are right. Weird too, they are not revolutionary ya know. Just a nice looking set of headers.

How strange.

Evolved8

Gents car is in service. My only complaint I have with the FF LT headers is the fact that they hit somewhere on the body under heavy exceleration and make a small rattle. Other than that I have No CEL's for Heater, 02s etc. Now we will see what happens when I get the report back soon from service on whats going on, But I soubt its the headers causing the isssue

benz_addict

It's only misfiring on one bank? Could be header gasket leak, could be as someone else mentioned a clogged cat. Happened to me.

Hammer Down

Still Waiting.......

theeddie

any updates?