Misfire issue continuing after replacing failed parts, need advice!!

So my check engine light came on & the engine was idling rough (sound familiar??) after I got home I pop'd the hood & could hear a massive air leak. After some disassembling I found a set of cracks in the upper & Lower intake boot. Replaced them & still had the air leak. Sprayed brakekleen at the DISC gasket & found it to be leaking. Replaced the O-ring & found that my butterfly valve was broken from the actuator arm & wasn't doing anything. So I removed the metal pin (the Anchor point that didn't fall out!) & removed the butterfly valve before reinstalling.

My question is, would removing that butterfly valve ( and the fact that the DISC is inop) cause my engine to continue to have a rough idle? Or is there something else I may have missed/overlooked?

I have not reset my codes nor hooked up to a scan tool, yet.

I have not inspected my CCV or secondairy air pump, but I'm 99% positive my VCG is leaking (on the passenger side rear corner)

Originally Posted by Eurofreak13

So my check engine light came on & the engine was idling rough (sound familiar??) after I got home I pop'd the hood & could hear a massive air leak. After some disassembling I found a set of cracks in the upper & Lower intake boot. Replaced them & still had the air leak. Sprayed brakekleen at the DISC gasket & found it to be leaking. Replaced the O-ring & found that my butterfly valve was broken from the actuator arm & wasn't doing anything. So I removed the metal pin (the Anchor point that didn't fall out!) & removed the butterfly valve before reinstalling.

My question is, would removing that butterfly valve ( and the fact that the DISC is inop) cause my engine to continue to have a rough idle? Or is there something else I may have missed/overlooked?

I have not reset my codes nor hooked up to a scan tool, yet.

I have not inspected my CCV or secondairy air pump, but I'm 99% positive my VCG is leaking (on the passenger side rear corner)

Yes. You will first need to replace the DISA with a properly operating one before going any further. The butterfly valve is essential to operation of proper air/fuel mixture for your engine to idle/run. Replace that and report back.

Gotcha!! Anyone have one for sale??

Originally Posted by basketthis

Yes. You will first need to replace the DISA with a properly operating one before going any further. The butterfly valve is essential to operation of proper air/fuel mixture for your engine to idle/run. Replace that and report back.

Untrue. The DISA valve changes the length of your intake runner from short to long to transition the engine from having higher torque to having higher horsepower and has nothing to do with AF mixtures. Regardless, replace it if it's broken.

Have you cleaned your ICV and checked your vacuum lines?

Go get codes read and post back up here.

Checked the vacuum lines going into the intake boot but nothing else.

Ok that makes sense about the valve changing the runner length, I notice it pulls much better from 3k to 6k but is sluggish down low.

Any other areas to inspect? Ill clear the codes today after work & see what pops up.

Originally Posted by SamDoe1

Untrue. The DISA valve changes the length of your intake runner from short to long to transition the engine from having higher torque to having higher horsepower and has nothing to do with AF mixtures. Regardless, replace it if it's broken.

Have you cleaned your ICV and checked your vacuum lines?

Go get codes read and post back up here.

Okay. My understanding was based off information from many different online sources and you know what happens when relying on that info...
On another note, when I pulled my disa valve all I could smell was fuel!

I didn't smell fuel but I did have a bunch of carb build up on the valve & in the intake mani.

Originally Posted by basketthis

On another note, when I pulled my disa valve all I could smell was fuel!

How recently was the car run before you pulled the valve? The fuel rail is right there and so are the injectors so you probably smelled the back flow from them.

Originally Posted by SamDoe1

How recently was the car run before you pulled the valve? The fuel rail is right there and so are the injectors so you probably smelled the back flow from them.

I had just turned the car off. This was a lot of fuel smell. It smelled like burnt fuel. There was a little smoke (similar to exhaust) coming out when I removed it.

Ok got the CEL reset & here are the codes that came back:

P1343 - misfire cyl #1 with fuel cut-off
P0300 (twice) - random misfire
P1348 - misfire cyl #4 on start up
P1352 - misfire cyl #6
P1345 - misfire cyl #2 with fuel cut off
P1346 - misfire cyl #3 on start up
P0174 - lean bank #1
P0171 - lean bank #2
P1351 - misfire cyl #5 with fuel cut off

So I'm thinking I've still got an issue with the intake system, any suggestions?

Originally Posted by Eurofreak13

So my check engine light came on & the engine was idling rough (sound familiar??) after I got home I pop'd the hood & could hear a massive air leak. After some disassembling I found a set of cracks in the upper & Lower intake boot. Replaced them & still had the air leak. Sprayed brakekleen at the DISC gasket & found it to be leaking. Replaced the O-ring & found that my butterfly valve was broken from the actuator arm & wasn't doing anything. So I removed the metal pin (the Anchor point that didn't fall out!) & removed the butterfly valve before reinstalling.

My question is, would removing that butterfly valve ( and the fact that the DISC is inop) cause my engine to continue to have a rough idle? Or is there something else I may have missed/overlooked?

I have not reset my codes nor hooked up to a scan tool, yet.

I have not inspected my CCV or secondairy air pump, but I'm 99% positive my VCG is leaking (on the passenger side rear corner)

My car had the exact problem rough idle and I did the same you did looked under the hood. I checked the upper and lower intake boots and found a couple tears in the upper boot so I replaced. Then I cleaned the the throttle and ICV with CRC throttle cleaner and reassembled everything and the rough idle was gone. Took for a drive and now it's been like 6hrs and still no rough idle. Don't if that would help.

Originally Posted by Eurofreak13

Ok got the CEL reset & here are the codes that came back:

P1343 - misfire cyl #1 with fuel cut-off
P0300 (twice) - random misfire
P1348 - misfire cyl #4 on start up
P1352 - misfire cyl #6
P1345 - misfire cyl #2 with fuel cut off
P1346 - misfire cyl #3 on start up
P0174 - lean bank #1
P0171 - lean bank #2
P1351 - misfire cyl #5 with fuel cut off

So I'm thinking I've still got an issue with the intake system, any suggestions?

You have a couple possibilities:

1.) Check the vacuum lines that go to the fuel pressure regulator on both the top side and the bottom by the regulator itself. Also check the ones going to the brake booster as well as the exhaust flap thingy in the back of the car.

2.) Your lower PCV drain hose is broken and is causing a big vacuum leak and poor running because of it.

3.) Your O2 sensors are done for.

4.) Your MAF is shot.

The unplug the MAF trick is really grasping for straws and might make the car run rough in itself...

Also, there's an air intake temp sensor between cylinders 3 and 4 on the intake manifold that has an o-ring as well. See if that guy is leaking...

Ok ill check that stuff out tomorrow. Options 1 & 2 & the intake temp o ring seem the most realistic.

Wouldn't a failed MAF cause a whole lot of problems & cause the engine to run horribly rough thru out the rpm band?

Would failing O2 sensors cause a intermittent CEL with rough running (trouble idling & lost of power thru the rpm band) then return to normal? Then ultimately fail causing a consistent idle problem?

There is a very real possibility that all these items have failed, as the car has a ton of miles, I'm just trying to follow your line of thought.

My line of thought is this. You are getting misfire and lean codes for the entire engine. That eliminates plugs and coils from the equation. You replaced the DISA, DISA o-ring, and intake boots. Provided that you installed all of those parts correctly, and I'm assuming you did, you have eliminated that part of the system. The IAT sensor o-ring is the last place short of the manifold gasket that could be leaking air into the system. So aside from the potential cracked vacuum hose or PCV hose, that leaves the other side of the system which are the O2 sensors or the other extreme that the MAF is shot.

Failing O2 sensors can certainly trigger intermittent CELs as they go in and out of range.

I'm not trying to have you buy a crap ton of parts, just leading you through diagnosis tactics.

FWIW, my bet is on the O2 sensors or the PCV hose. The IAT o-ring is a long shot but it's a cheap and easy replacement part at ~$0.50ish.

I appreciate all the info & advice your sharing with me! Plus I'm following your thought process with damn near the same logic. All the misfires have to be from an air leak or incorrect air metering. If I was getting misfires without getting a lean (or rich) reading from bank 1 or 2 then I would think the O2's are dead.

What about a failing (leaking) VCG or how about my secondairy air pump? Would that throw its own set of codes?

I'm going to dive into this problem in the next couple of days so I will definitely report back what I find

Thanks again for everyone's input!!

Originally Posted by Eurofreak13

I appreciate all the info & advice your sharing with me! Plus I'm following your thought process with damn near the same logic. All the misfires have to be from an air leak or incorrect air metering. If I was getting misfires without getting a lean (or rich) reading from bank 1 or 2 then I would think the O2's are dead.

What about a failing (leaking) VCG or how about my secondairy air pump? Would that throw its own set of codes?

VCG would throw oil pressure errors and SAP has it's own codes.

O2 sensors can send bad signals and throw lean/rich codes without actually failing to so to speak. If they are totally dead, you'll simply get an O2 sensor code.

Ok is there a seal where the arm the operates the butterfly valve in the DISA? Because everytime I spray that arm (or in that area) I can hear the engine idle pick up & the engine smooths out. I'm thinking the valve is my issue!! Or the ICV gasket but I believe it goes into the intake 180deg from the inlet side in the intake boot (not 90deg into the mani near the DISA valve)

Damnit do I have to buy one from the dealer?!?!? Man that's gonna sting haha

That sounds like you've potentially solved the problem. Yes you'll have to get one from the dealer or another online part store.

Good luck!

GOT IT!!! haha ****ing DISA valve I hate you! Ok I patched the "hole" where the valve attaches to the arm & vacuum leak be gone. Unfortunately now I have to buy one. Thanks the everyone who helped & samdoes1 your the man!