My SES light is on and I ran the codes using the low tech method (counting the number of times the light flashes). I've got a 455 and 1448 (EVAP Canister Vent Control Valve Open and EVAP Control System Gross Leak). My understanding is that having these codes is a pollution control issue and in no way affects driveability or performance.

At the same time, my car is quite sluggish at times. One damp day from a dead stop, I let the clutch out and mashed the throttle and the car was very very sluggish until about 3500 rpm. If I tried that when I first bought the car, the tires would struggle to maintain traction and then start to spin at high rpm. Now, the car has 108,000 km on the odo and it doesn't seem as powerful as it used to be. If I mash the throttle at say 2500 rpm in 5th gear, the engine seems lethargic and often seems to skip (seems like a plug isn't firing)

Anyway, when I spoke to the service rep at the stealership, he suggested that the two might be related. I told him about the codes I pulled and he stated that the diagnostic tool they use can uncover somethings that I can't. Is this true? If I let them run the tests, it will cost me about $90 and I suspect, will not solve the issue of lack of performance. I thought about changing the plugs, but the maintenance schedule doesn't call for a change until to 160,000km.

What should I do? Unfortunately, the closest stealership is 2 hours away.

Thanks in advance for your help.

 

The two problems are NOT related. the first one just purges your fuel vapers from going into the o-zone. The hose running to your tank could be completely removed and it will have absolutely no effect on driveability.

Gross evap leak means it's a rather large leak. 99% of the time your gas cap wasn't on tight, which didn't allow the pressure to build and the sensor picked it up.

Last time you changed your plugs did you use OEM brand platinum? They are right that they can see things you can't. They may/may not be able to diagnose your lack of performance issue. Make sure your gas cap is on straight and tight, reset the code. It will probably go away. As far as performance, that could be a # of things.

 

Thanks for your reply 5thgenmaxima. I've reset the SES and tightened up the gas cap may times; usually when I fill up. Unfortunately, the light comes on before the tank is half empty. I have never changed my plugs as I've got 52,000 km before the manual says so.

 

Pull and inspect one of your front plugs. Look online you'll find many of articles searching on google that give examples of different engine conditions by looking at your plugs. Compare your plug to one on the list and it will tell you alot about your engines condition. (obviously the condition of the plug) weather you're running rich, lean, have detonation problems, etc)

108KM = roughly 68,000 miles. They say you can get 100K out of platinum plugs, but if your running your engine hard and under constant load you may want to do it sooner. (around 100KM)
May or may not fix your problem, but it would give you a good starting point.

As far as your gross leak, if the light keeps coming back on first inspect your gas cap to make sure the seal isn't messed up. There are two different types of evap leaks. Gross and I forget the other.
The system is capable of detecting leaks to .020 or larger. (or .040 depending on your car)
A gross leak usually means the leak is larger than (IIRC) .080.

Since you have another code p0445, I would suspect this is PROBABLY causing the p1448 problem. If you fix your canister control valve problem it will PROBABLY fix your evap leak. (your canister valve is "stuck" to open constantly purging your system not allowing pressure to build)

Any other local shops??
Unfortunately the only way I know how to check to see if the control valve is bad and sticking open or if there is an electrical problem is to command the valve closed w/ a scantool and use a multimeter at the valve to see if it changes. Maybe someone else can chime in on how to test it and/or if a common problem w/ our maximas is the valve or circuit.

 

Ok, I've taken enought from this site. So, I came up with a way to check it at home for ya. BTW:

I took this from alldata

(basically power should only be going to the valve when it is running its test)


Here's alldatas procedure to check

Since you do NOT have a consult laying around this is what I would recommend.

NOTE: FIRST VERIFY THRU EITHER ANOTHER ORG MEMBER OR THE DEALER THAT YOUR EVAP VALVE NEEDS A 12V SOURCE AND NOT A 5V SOURCE!!!!!!!!!

skip steps a-f
Grab some back probes. (paper clips work very well if no back probes are availiable)

Put the back probes into both of the evap wires and run some speaker wire to ground and + on your battery terminals. Verify your canister valve opens/closes by following steps G-***... Any time it says to press "on" with the consult simply put power directly to your evap from the battery. Anytime the test above says "off" simply take power away from the valve.
(also as another disclaimer, since you will be putting power to the evap and backprobing the wires this will also send power/ground thru those wires. I do this quite often w/o disconnecting the wires. However it is recommended when you do it "by the book" that you unplug that harness, so make sure you don't hook them up backwards. However since you probably do not have another chopped up harness to plug into your evap this will work, but it's not a recommended procedure)
ANOTHER NOTE: IF YOU USE PAPER CLIPS AND SPEAKER WIRE DO NOT ALLOW THE + TO TOUCH THE NEGATIVE. BEND THE PAPER CLIPS OPPOSITE OF EACH OTHER AND TAPE THEM OFF SO THEY HAVE NO CHANCE AT MAKING CONTACT WITH EACH OTHER