[Treyus30]

Hi all,

For two months since I bought my 03 Tracker (J20) I've been unable to get the Evap and Catalyst systems "ready" for emissions testing so I'm driving on an expired temp plate at this point. You can pass an '03 with 1 system 'Not Ready' in my state, but not 2.

I was originally just hoping drive cycles would clear the Evap system, but no dice, so I'm moving to why the Catalyst system would be frozen. I checked the O2 sensor signals yesterday (the front looks band new so P.O. must have changed it) and the front signal looked ok for the most part, but the back was basically stuck around 0.1V.

I'm assuming this is a problem and seems to be from what I read in the service manual, but want to hear some opinions since I would expect this to have thrown a code at this point, but hasn't. I also get like 17mpg, which is low IMO for this car. Could I actually need a new cat, or is this certainly a bad sensor?

 

[2013GV]

Post cat should be steady ish around 0,5 to 0.7 volts. Slowly oscillating

 

[Treyus30]

Post cat should be steady ish around 0,5 to 0.7 volts. Slowly oscillating

That's what I thought. So...bet on sensor or cat?

 

[2013GV]

If sensors not cycling then its usually the sensor. They do age and die. Sensor is a maintenance item and should be replaced every 90,000 miles or so

 

[Treyus30]

If sensors not cycling then its usually the sensor. They do age and die. Sensor is a maintenance item and should be replaced every 90,000 miles or so

Got it. Thanks.
I'll come back in a week if it's still not "Ready" haha

 

[2013GV]

Just remember fuel tank between 25 and 75% level otherwise the evap won't set. I'm betting your sensor has finally died. Keep us posted.

 

[aquanaut20]

Do you have a MIL on and have you checked for PENDING codes..

 

[Treyus30]

Do you have a MIL on and have you checked for PENDING codes..

No, yes

 

[aquanaut20]

The CAT will not set if there are others not run, so find why the EVAP has not set, Check the integrity of the purge valve, canister vent valve, tank pressure sensor, filler cap and lines,

 

[Treyus30]

The CAT will not set if there are others not run, so find why the EVAP has not set, Check the integrity of the purge valve, canister vent valve, tank pressure sensor, filler cap and lines,

Well that's annoying if true.

So with the Evap:

• originally the MIL bulb was crushed by PO and had shorted a few things (a mess I won't go into)
• MIL code was active for Evap when I bought it and I cleared it
• I drove 200 miles, through a whole gas tank hoping Evap system would get ready. It didn't.
• I rebuilt the head/timing chains/etc and finished last week. Noticed when disassembling the purge valve had a hose disconnected, so I concluded that was probably why the MIL was active originally, but I have not had the MIL come back for anything other than a TPS after the first crank after the head gasket replacement last week.
• I've driven about another 50 miles since then
• I replaced the fuel filter a few days ago and didn't notice anything wrong by the fuel tank, but I'm not sure where tank pressure sensor or canister vent valve is.

So basically I just keep waiting for the Evap system to do something... anything... but it won't.

 

[Treyus30]

So, I'm actually not going to order a new downstream O2 sensor given what aquanuaut20 is saying, and this Lambda sensor - pre- & post- catalytic converter
shows that what I'm seeing is what I'm supposed to be seeing.

 

[2013GV]

Remember fuel quantities and its a couple of full drive cycles too, including city and motorway driving

 

[L84sky]

I'm not sure where tank pressure sensor or canister vent valve is.

On my car the pressure sensor is on top of the fuel tank.

The canister vent valve (23) is on the back of the EVAP canister.

 

[Wildebeasttuning]

Since the evap systems works off vacuum, did you look into the possibility of the gas cap not sealing properly? Assuming that the vent valve is functioning.

 

[aquanaut20]

Covered in post #7

 

[Braxas]

Hi all,

For two months since I bought my 03 Tracker (J20) I've been unable to get the Evap and Catalyst systems "ready" for emissions testing so I'm driving on an expired temp plate at this point. You can pass an '03 with 1 system 'Not Ready' in my state, but not 2.

I was originally just hoping drive cycles would clear the Evap system, but no dice, so I'm moving to why the Catalyst system would be frozen. I checked the O2 sensor signals yesterday (the front looks band new so P.O. must have changed it) and the front signal looked ok for the most part, but the back was basically stuck around 0.1V.

I'm assuming this is a problem and seems to be from what I read in the service manual, but want to hear some opinions since I would expect this to have thrown a code at this point, but hasn't. I also get like 17mpg, which is low IMO for this car. Could I actually need a new cat, or is this certainly a bad sensor?

Since the evap systems works off vacuum, did you look into the possibility of the gas cap not sealing properly? Assuming that the vent valve is functioning.

I was going to add that any vacuum leak will be detected and as the hoses are almost 2 decades old it would be a good idea to check all under the hood. They may appear to be ok but may have a split somewhere. Also i have noticed on some vehicles they use plastic for short runs to vacuum lines and its possible a gracked plastic juction has brokem. It takes quite a noticable vacuum loss to trigger an evap code, such as a brake booster hose left off, etc...
As for the 02 putting out 1V, replace it, these are maintenence items, and always do them together bank 1 / bank 2

 

[L84sky]

I'm actually not going to order a new downstream O2 sensor given what aquanuaut20 is saying, and this Lambda sensor - pre- & post- catalytic converter
shows that what I'm seeing is what I'm supposed to be seeing.

From the link you provided: "The post catalytic converter sensor signal Channel B remains around 0.1 V, indicating a lean output from the catalytic converter, "

The downstream O2 signal from my good engine is a flat line at around 600mV. I can't tell if your 100mV signal is due to a bad sensor or an actual lean condition.

 

[aquanaut20]

It takes quite a noticable vacuum loss to trigger an evap code, such as a brake booster hose left off, etc...

What gave you the idea that a vacuum leak will produce an EVAP code ??

 

[aquanaut20]

From the link you provided: "The post catalytic converter sensor signal Channel B remains around 0.1 V, indicating a lean output from the catalytic converter, "
I can't tell if your 100mV signal is due to a bad sensor or an actual lean condition.

Or, A bad circuit, only testing will reveal the truth.. you could gamble and throw a sensor, let us know..

 

[Braxas]

What gave you the idea that a vacuum leak will produce an EVAP code ??

Had a code that gas cap was loose, evap system, ended up being brake booster hose slipped off slightly