Secondary air/ EVAP monitor

  • 2001 CHEVROLET S-10
  • 128,100 MILES

I just bought a 2001 s-10 2.2 5 speed manual. Ive done countless drive cycles but cant get the secondary air and evap to pass. The vent solenoid is actuating and the secondary air pump is working. All fuses are good. No check engine light and no active or pending codes. What could be the problem?

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have the same problem?
Wednesday, January 4th, 2012 AT 11:00 PM

1 Reply

  • 4,241 POSTS

Do you have the capability to see what dtc tests have run and passed, and/or run and not passed? It should be available on the scan tool. Once you have determined which have either not run, or not passed, you can look at the criteria for running the test, and see if there are specifics that are not being met.

Here is the typical drive cycle that I have shown, see if there is anything different than what you are doing.

Typical OBD II Drive Cycle

Diagnostic Time Schedule for I/M Readiness

Vehicle Drive Status

What is Monitored?

Cold Start, coolant temperature less than 50 C (122 F)

Idle 2.5 minutes in Drive (Auto) Neutral (Man), A/C and rear defogger ON

HO2S Heater, Misfire, Secondary Air, Fuel Trim, EVAP Purge

A/C OFF. Accelerate to 90?Km/h (55?Mph), 1/2 throttle.

Misfire, Fuel Trim, Purge

3 minutes of Steady State - Cruise at 90?Km/h (55?Mph)

Misfire, Secondary Air, Fuel Trim, HO2S, EVAP Purge

Clutch engaged (Man), no braking, decelerate to 32?Km/h (20?Mph)

Fuel Trim, EVAP Purge

Accelerate to 90 97?Km/h (55 60?Mph), 3/4 throttle

Misfire, Fuel Trim, EVAP Purge

5 minutes of Steady State Cruise at 90 97?Km/h (55 60?Mph)

Catalyst Monitor, Misfire, Fuel Trim, HO2S, EVAP Purge

Decelerate, no breaking. End of Drive Cycle

EVAP Purge

Total time of OBD II Drive Cycle 12 minutes

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Thursday, January 5th, 2012 AT 4:17 PM

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