Check engine light is on. I took the baby to AutoZone. Following problem detected by OBDIII:
1. The PCM has determined that a small leak exists in the evaporative emission control system.
Possible Causes:
 Defective or loose fuel cap
 EVAP canister or hose cracked-not connected
 Purge or vent solenoid defective
 Vacuum leak at engine
2. The PCM has determined that the main catalyst efficiency for bank 1 is below threshold for the current engine operation conditions. (Bank 1 identifies the location of cylinder #1, while bank 2 identifies the cylinders on the opposite bank)
Possible Causes:
 Catalytic converter defective
 Engine misfire or running condition
 Large vacuum leak
 Engine oil leakage into exhaust-valve guide seals, piston rings
The light has been there for about a week. Based on above information, can anybody suggest what is the next step I most likely to take? Which parts do I need to check for the problem? [/align][/align]I used to have 'Check Engine' light on, but with a message like 'Emission System Failure....." -- I don't remember the exact text. It usually disappears after tightening the gas tank cap. Now the light is on without any message showing up and tightening the gas cap does not work. I can not feel anything wrong when driving.

This is a 2001 model with 116k mile on it. It has had 35k trouble free miles since I bought it. I hope I can do something to it with some trouble shooting tips from you guys before I have to take it to a dealer. Help me please. Many thanks!

plopband[/align]

 

The scanner I used to use at a dealer could tell you when each code was stored and how many times each fault occurred.

A fault can be permanent or intermittent.

This is useful because a fault can be set once (gas cap was left loose) then the fault can be fixed (gas cap now tight) and this may not be a code worth worrying about. All this could happen and a code will still remain in the computer memory.

The catalyst efficency code in my experience is the catalytic convertor is the fault if there are no other fault codes from misfires or fuel mixture "out of range". However, I don't know of a good way to troubleshoot failing cat. conv. other than replacing it, and they are expensive.

Hope this helps

B

 

Thanks Tripleb. I think what you said is right. I also want to know which part is about the 'vacuum', and how to check if there is a leakage on it?

 

How is the car running? What I would do is have the guys at AutoZone clear the codes for you (they usually will do this, or show you how to di it yourself. Then drive the car and see if the checke enbgine light comes on again. If it does, get the codes read again. Any reapeat codes defiinitely point to a problem. I've found over the years that a lot of error codes are one time "glitches" that will set the check engine light the first tiem, but then never re-appear after they have been cleared.

Good luck and keep us posted.

Glenn

 

On the 2001 V70's a bad set of injectors will also set a Cat code.
I have seen it many many times.
The the 2001 Model year came out we used to see the codes all the time with no fix.
Even a new Cat wouldn't fix it. Finally they figured out it was bad injectors.
But if you leave the code for to long without replacing the injectors it will destroy the Cat and you will need to replace that to.

 

The vacuum system comprises of the intake manifold, and all the hoses, gaskets, and piping that are attatched to it.

There are several ways to diagnose a vac. system, here are a couple.

You can pressurize the system, but you need a special tool and a air compressor, but I like the eyes and ears personally. Listen for a hissing noise and look for hoses that are cracked or have come off. Check that all clamp are tight, especially the intake pipes from the Air Mass Meter (MAF) to the throttle body. This will include intercooler hoses on a turbo.

A spray bottle with water can do a pretty good job, just spray around the intake gasket and the hoses, if there is a leak, the engine shoul stumble when you hit the leak.


Hey tech, great info, I can't say we had that experience in California, but I may have missed it. Was there something that tipped you off to the injectors? Was there a measurable difference between the old and new ones?

 

Thanks guys! I think your suggestions are really helpful. The first I would like to do is to check any leakage on intake part. If it does not work, I have to take it to a dealer to check the Cat and injectors. Actually the car is running the same as before, at least I can not feel any difference.

 

They wouldn't share much info with us.
The only difference I know of is the old injectors are yellow and the new ones were green with a red tab on them.