Emissions Test Issue

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

EddieC

Full Access Member
Joined
Aug 9, 2014
Posts
649
Reaction score
513
I recently had an error code related to small evap leak and circuit failure.
I cleaned the gas tank filler neck and cleared codes about a week ago.
No codes have returned.

I went in for the biannual emissions test today (plug in test) and it failed because it noted three "not ready" notations in the test report; Evap System, Oxygen sensor, Oxygen sensor heated.

The technician asked if the vehicle has sit around for much time or has not seen highway use (because there is no history in memory)?
The answer to that is that it only sees about 15 local miles a day and generally no highway use.
He suggested running it down the highway for 30 to 40 miles because all of the three system issues were related to highway driving.

Is that a reasonable assessment?
Or perhaps because error codes were cleared about a week ago and not many miles have been put on the truck since?

The truck starts and runs fine and, as noted, no codes have returned.
 

Doubeleive

Wes
Supporting Member
Joined
Nov 7, 2017
Posts
26,242
Reaction score
39,332
Location
Stockton, Ca.
I recently had an error code related to small evap leak and circuit failure.
I cleaned the gas tank filler neck and cleared codes about a week ago.
No codes have returned.

I went in for the biannual emissions test today (plug in test) and it failed because it noted three "not ready" notations in the test report; Evap System, Oxygen sensor, Oxygen sensor heated.

The technician asked if the vehicle has sit around for much time or has not seen highway use (because there is no history in memory)?
The answer to that is that it only sees about 15 local miles a day and generally no highway use.
He suggested running it down the highway for 30 to 40 miles because all of the three system issues were related to highway driving.

Is that a reasonable assessment?
Or perhaps because error codes were cleared about a week ago and not many miles have been put on the truck since?

The truck starts and runs fine and, as noted, no codes have returned.
ya when the codes are cleared it reset's all the sensors so they show "not ready", just drive it and check it with a code reader in a few days and then take it back when they are ready
 
OP
OP
EddieC

EddieC

Full Access Member
Joined
Aug 9, 2014
Posts
649
Reaction score
513
ya when the codes are cleared it reset's all the sensors so they show "not ready", just drive it and check it with a code reader in a few days and then take it back when they are ready
I don't ever recall seeing where to look to if anything is "not ready" on my reader.
Any idea where to look?
I generally just go to read current codes and lately the report is "no codes".
 

Doubeleive

Wes
Supporting Member
Joined
Nov 7, 2017
Posts
26,242
Reaction score
39,332
Location
Stockton, Ca.
I don't ever recall seeing where to look to if anything is "not ready" on my reader.
Any idea where to look?
I generally just go to read current codes and lately the report is "no codes".
depends on your scanner, many have a display like this one with little indicators green is ready, red is not ready, the tech2 has a im readyness menu, it is different than the small handhelds
61.jpg
 

Fless

Staff member
Super Moderator
Joined
Apr 2, 2017
Posts
11,895
Reaction score
24,218
Location
Elev 5,280
depends on your scanner, many have a display like this one with little indicators green is ready, red is not ready, the tech2 has a im readyness menu, it is different than the small handhelds
View attachment 437553


^^ This ^^ Look for something like "I/M Readiness Monitors" or "I/M Monitor Status."

EDIT: I/M = inspection/maintenance
 
Last edited:
OP
OP
EddieC

EddieC

Full Access Member
Joined
Aug 9, 2014
Posts
649
Reaction score
513
depends on your scanner, many have a display like this one with little indicators green is ready, red is not ready, the tech2 has a im readyness menu, it is different than the small handhelds
View attachment 437553
I don't have anything that looks like that.
When I scan for "other codes" (vs current) some of the readings say "not tested" since last start. Maybe that is a clue.
I'll research if it has readiness status reports though. Darned thing (Autel MD906 Pro) didn't come with a manual but there probably is one out there.
 
Last edited:
OP
OP
EddieC

EddieC

Full Access Member
Joined
Aug 9, 2014
Posts
649
Reaction score
513
Back on this.
Going back, a P0449 error code occurred and was reset just before the the emission test at the start of this thread so I assume that is why the EVAP "not ready" reports came at the emissions code.

As a shot at the code, a new oem vapor canister purge valve (atop engine) was installed.
Since then, no code, and we've been driving, probably 300 miles or so in the past three weeks since the test and planning on checking the "readiness" and get retested today (neither happened) because the P0449 code returned today.

First question, would the P0449 code be delayed by the potential "not ready" status that may have just changed or would it have come back right away weeks ago after the previous reset if there was a fault?

So today after resetting the code again the truck was driven a total of 45 miles on the highway (55-60 mph) as suggested by the emissions inspector to get the EVAP sensors "ready". Unfortunately it was segmented twice by short on/off ramps to get the miles.
Got home with about 70 miles from reset and OBED EVAP seen as "not ready". Not planned, but the gas tank started out as full which is contrary to what was advised above.

Any idea how many miles or amount of time is needed to get the sensors active?

Maybe I need to chase other parts in the system while waiting it out.
 
Last edited:

mikez71

Full Access Member
Joined
Mar 9, 2023
Posts
1,371
Reaction score
1,612
Looking online, that code seems to mainly indicate a bad vent valve?
I believe I have seen that mentioned somewhere here as well..
 

Forum statistics

Threads
132,364
Posts
1,866,745
Members
96,985
Latest member
LeanMachine

Latest posts

Top