Smog Test on a 4x4 auto

[Essex4x4]

Okay so as you can see i have an 06 4x4 and i have a question. I am no where near needing a smog check i just have a question. Since the newer Explorers have auto 4x4 how do they do the smog check. The place i have gone in the past only has a place for one set of wheels. When they start the test wont the computer engage the front axle because the rear wheels are in a way slipping. I mean the rear wheels would be turning and the front wheels are not.
How do they do a smog on an auto 4x4?

 

[Blee1099]

Most states today will just plug into to OBDII port and run the vehicle for 3-5 minutes.

 

[98rffridr]

If Iam correct 4x4 can be selected so that you could tun 2wd on. If you have AWD with a non transferable transfer case then you would indeed need a AWD Dyno. or all you have to do is uninstall the front drivshaft

 

[jupiterak]

Most states today will just plug into to OBDII port and run the vehicle for 3-5 minutes.

He's correct and they also do a visual inspection as well.

 

[Essex4x4]

If Iam correct 4x4 can be selected so that you could tun 2wd on. If you have AWD with a non transferable transfer case then you would indeed need a AWD Dyno. or all you have to do is uninstall the front drivshaft

newer 4x4 explorers have 4x4 auto which engages the 4 High automaticaly when the rear slips.

Whats a AWD Dino?

 

[aaronajb1981]

AWD Dyno = All Wheel Drive Dyno.

 

[joecrna]

In CA there are two options. If the shop has an AWD dyno, they do both speeds on the dyno just like with two wheel drive. If the shop has only a two wheel dyno (practically all shops as an AWD is extremely expensive) They put the vehicle in park or nuetral and run the engine at two slightly different rpms with the engine not loaded. Not exactly a fair comparison but thats the CARB way.

 

[Essex4x4]

In CA there are two options. If the shop has an AWD dyno, they do both speeds on the dyno just like with two wheel drive. If the shop has only a two wheel dyno (practically all shops as an AWD is extremely expensive) They put the vehicle in park or nuetral and run the engine at two slightly different rpms with the engine not loaded. Not exactly a fair comparison but thats the CARB way.

So, when i actually have to go get a smog, they won't put it on the dyno? The one at the place i go to is only a 2wd dyno, not a 4x4 dyno.

 

[joecrna]

Correct. CARB allowed this to decrease the resistance to requiring smog shops to get dynos originally. A four wheel dyno would have been much more expensive for them.