Hey i have a constant 0401 code for EGR insuffiecient flow, and now today my idle is rough and caused a new code which is 0300 and is random cyliders misfiring. that shows with my idle being rough. Its a 03' with 132k Any help with what to do for the 0300??? And the 0401???

 

I would start by checking for boost leaks, and make sure all of your vacuum hoses are connected properly.

 

I had my intercooler pipe keep blowing off my intake manifold so i got better t clamps and thats fine... The 0401 code didnt cause a issue yet but just today that 0300 code popped up and idle is very rough. Should i replace the spark plugs? thats what i see alot of ppl saying.

 

look at egr your vacuum line might popped off.kind of hard to reach but worth it.

 

I mean, spark plugs are also easy to check, you could always pull them to see if they are fouled. If you know you were already popping couplers off and stuff a boost leak test and making sure all of your vacuum stuff is hooked up is really a smart idea.

 

+1 same things happened to me and it threw the same code. It's a very small nipple on the back of the intake manifold on the driver' side. Ziptie it up.

 

Ok tomorrow ill just take a look at the EGR fully and once i reconnect it i hope the 0300 code will go away, ill leave a comment tomorrow and let you all know what happened, thanks. Also does anyone have a link i can go to with a step by step process or can tell me how?

 

I have a code 0300 now and thats becuase I have stage2 cams

 

I think not---misfires are not because of cams, plugs and tune yes, cams no.

 

So not only could my lines for the EGR be off or bad but my plugs as well?

 

Or it could be because you drive an '03 Evo. Go search on the p0300 code and then check what year car the person with the complaint is driving.

 

Check these:
1. Lines for EGR
2. IAC - Idle Air Control - this controls the amount of air in the TB at idle. Its also a known problem on '03 models. Mitsu redesigned it on later year models
3. EGR - with that many miles it might be time to replace it

Best thing I did was remove the EGR system altogether. Eliminates a lot of clutter and failure points. Eliminates dirty exhaust air into the intake manifold and lowers intake temps since the TB no longer has to be cooled with engine coolant.

 

So im pretty sure i fixed the problem... spark pulgs werent in all the way... car runs normal at idle again, check my egr and turns out owner before me already took it out. It just has that cap deal so thats why im sparking that 0401 code. Thanks everyone!

 

Yup this what happen to me. It's right be hind the throttle body just feel for a little nipple and the hose that poped off.

 

When you say your spark plugs weren't in all the way, do you mean you didn't have them THREADED in all the way, or your boots weren't on all the way?

If they weren't threaded in all the way, be careful not to do this with a hot engine, as you can ruin the threading in the motor. Also, hopefully they weren't cross threaded... hopefully you were just in a rush to get them done and didn't thread them in all the way.

There's a post just a few up from this that I just commented on P0300. As barney says... it's common. Go check in there for some advice, or search google.