suppose one of the hose is loose, assuming we erased the the fault, so the moment we drive the car a fault code should be thrown.right? or u will cruise for a while then the code will show?

 

Not sure, but I believe the nature of a CEL is that it requires so many faults to be logged before it'll throw a code. Therefore, it won't come on immediately but after a bit in many cases.

 

It can take as long as 20+ miles to come on, as in my case.

 

thats whats happening with me !

 

I bought a Creader on eBay for $34 shipped and got the P0401 code. I popped that little number into the search and this thread popped up. I went out to the parking lot and sure enough the hose was off the port facing the passenger side of the car. I popped it back on and I am in business.

On a side note my mileage took a severe hit when I first noticed the CEL.

 

Im still battling the code. I changed the valve yesterday and after 40+ miles....BAMM...CEL. I think I have narrowed it down to the solenoid. I have cross-checked the vac hoses with other evos and I even know them by heart now. My mileage didnt suffer. I still get 260 for the tank

 

You missed the part where I said "Rev the car and see if the solenoid pulls vacuum"

 

a little more specific....?

 

Post #87, I believe.

 

See post #88. I got a valve from a friend (FREE)and installed it, even after the testing because I wasnt convinced. code came back in a few miles. (3-5 starts maybe). I BOUGHT a new solenoid and installed it Saturday. I don't want to write about this because I might drive tommorow and BAM...just my luck. ( I think this might be it). 10-15 starts and approximately 90 miles so far.......no code (knocking on the biggest piece of wood I can find)

 

wow! another happy reader. threw the cel once. had it checked, mitz said my o2 sensor was going bad and wouldn't replace it, blaming my intake FILTER (yes i said FILTER) for the reason that the sensor would go bad. but I was still cerious as to why i was running so rich. Im sure this is the culprit. im gonna check it out tomorrow morning

 

well mine poped off, talked to AL, found a vac hose dangeling and poped it back on. ok now what i dont understand is, how the hell did u guys get zip ties on them? did u all take off your UICP to get to them?

 

found out this wasn't my problem. both hoses were on quite tightly. could this same problem happen because of a failing o2 sensor? the car is running great, just really rich. I threw the code once, cleared it, threw it again and it cleared itself this time. the second time it only came on for maybe 45 mins running time. would replacing the o2 sensor make it run less rich. and fix the problem.

 

thats the next step. either that or i have herd that the EGR's can get dirty. i think the o2's for our car are like $250, crazy!

 

Its expensive if you go to the dealer. I know, because i did much research and found a brand that worked. NTK is the name. I paid $56 for an PLUG-UP (not spliced) o2 sensor (front...shipped to me in 2 days). Let me look for the the thread and link.

BTW. Since I changed my sensor, my gas mileage went way up. 21-23 mpg now (mixed driving)

brb........