XJ California Exhaust System

[AZJeff]

My MJ has the engine from a 2000 XJ in it, and it has the California emissions system on it.

 

I see two "mini-cats" just off the exhaust manifold, with pre and post cat O2 sensors.  What I do not have is a second "main" cat converter further downstream.

 

The FSM is contradictory here.  It shows a main cat like all the "49 state Federal" in place along with the mini-cats, but the wiring diagrams do NOT show O2 sensors associated with the main cat., only with the mini-cats.

 

So do the CA XJ's have three cats?  If they do,does the main cat have any O2 sensors?

 

i have to get the exhaust system right to pass emissions testing here in AZ.

[AZJeff]

Nobody knows?   Eagle, you are a wizard on XJ's as well as MJ's.   Do you have any clue, or know anyone on other forums who would know?

[Ωhm]

R U A V6, if so, I don't see no DTC's posted for a 3rd cat.

[AZJeff]

1 hour ago, Ωhm said:

R U A V6, if so, I don't see no DTC's posted for a 3rd cat.

A V6?    A 2000 XJ never came with a V6, only the 4.0 in-line six.

 

My FSM lists the following codes:

P0143 (M)    1/3 O2 Sensor Shorted To Ground

P0144 (M)    1/3 O2 Sensor Shorted To Voltage

P0145 (M)   1/3 O2 Sensor Slow Response

P0146 (M)    1/3 O2 Sensor Stays at Center

 

Since they talk about O2 sensors 1/1 and 1/2, as well as 1/3, I thought it might be a sensor related to a third cat.

 

I am still confused.

[Jeep Driver]

I don't if this will help you or not.....

 

http://www.jeepforum.com/forum/f11/o2-sensor-confusion-1498743/

 

 

https://www.cherokeeforum.com/f2/number-o2-sensors-2000-a-76025/

 

https://www.cherokeeforum.com/f2/o2-sensor-location-163287/

[sinkrun]

Two upstream o2`s in the exhaust manifold and two down stream just below the two mini cats nothing down on the third.

[AZJeff]

Thanks, "JeepDriver" and "Sinkrun"   Those two details explain a lot that seemed a little unclear from the FSM.

 

So it looks like I have all of the O2 sensors and wiring needed, along with the mini-cats.  What I don't have is the "main" cat located downstream between the trans. mount and the muffler.   I guess I have some shopping to do if I want to pass an emissions test.

[gogmorgo]

Just curious, has any AZ emission tech actually told you your exhaust isn't compliant?

[AZJeff]

2 hours ago, gogmorgo said:

Just curious, has any AZ emission tech actually told you your exhaust isn't compliant?

No, not yet.  I have been debating this myself.  Maybe when they "sniff" the unit (which is registered as a 1989), they will find it complies.

 

The only thing stopping me right now is that the vehicle has no brakes, and I am waiting for parts to arrive to complete that task.

 

Maybe I will take it to the emissions test station and see how it goes....

[JeepSchmidt O'Guinness]

I thought there was something offered like diagnostics procedure's before you actually do the inspection test which can label your title as a gross polluter?

[AZJeff]

On 7/22/2018 at 11:22 AM, JeepSchmidt O'Guinness said:

I thought there was something offered like diagnostics procedure's before you actually do the inspection test which can label your title as a gross polluter?

If there is such a thing, there is no information on it anywhere on the Arizona DMV or Arizona Dept. of Environmental Quality websites.

 

I cannot find any exceptions for vehicle age, etc. and I am unlucky enough to live in an area of this state that requires emissions testing.

[Ωhm]

Can you read OBD codes? Do you have "Check Engine" lamp? Found this link, maybe you did too.

http://www.myazcar.com/obd-check-engine-light

[gogmorgo]

If it's only certain parts of AZ it might be county bylaws, not state.

[AZJeff]

My address is in the area that requires an emissions test.  If I lived 2 miles east of here, I would be exempt.

 

Since I am not roadworthy right now without brakes, I am not too concerned yet.   I will probably take it in and have it tested with just the front two California cats, and see if it passes.  I will also investigate the exemption mentioned in the link by "Ohm"

 

Standby for more details later.

[Longview]

Fiancee drives a 2004 cali LJ.

2 cats on manifolds for both banks. O2s before cats for fuel mixture, O2s after cats for cat efficiency. 1 cat under the jeep, not monitored before or after.

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