vez

The mechanic told me that he reset DTC codes.
He did know when the monitor will set itself to issue more codes if any.
I thought that I might have to drive 300 miles. Then to bring it in again to see if the monitor is set for issuing codes.
This seems ridiculous.

parkers Z28

I'm assuming that your trying to get your car inspected ???
Drive it 100 miles and take it back to see if it will pass inspection .... if the engine light comes back on you have a problem . there is a sticky for free scan software on here in the computer diagnostic section.....do you know what DTC codes you were having ?

vez

Thanks Parkers.
Yes, this is for emissions cert in Virginia.
The codes were
P1258 Engine Coolant Overtemperature - Protection Mode Active
P1416 AIR System Bank 1

The car overheated last year when I broke a belt. It has not overheated since. But I notice the radiator light come on even though it's full and temp is fine.
The mechanic assumed the Overtemperature code threw when it over heated last year.
They mechanic replaced the O2 sensor hoping solve the AIR System Bank issue. He reset the codes and told me to drive it until the monitor resets.
Today I drove it and the Radiator light came on and then the Check Engine light came on again. The temp still is good. Maybe the reservoir is low...
It's a '98 5.7 Z28.

parkers Z28

The low coolant light is a typical problem with these cars.. normally its just the low coolant light
sensor on the radiator sometimes you can clean the sensor and it will work properly
do a search on here for (shoebox look) at his signature click on (how to's) lots of good information
in there. www.shbox.com

vez

Do you think that dirty low coolant sensor would also make the Check Engine light go on?
Thanks!

Jonathan Lucas

I just have to add this because i tackled this today..
1416 is AIR Check Valve Passenger side. Replace it.. 10 - 15 dollars.. when you replace it, unbolt the metal tube from the exhaust manifold, and make sure there are no obstructions, and in the exhaust manifold... this is only used for cold start conditions, to introduce unburnt pollutants into cat converter.. when the AIR pump does the self check, and when certain conditions are met..

Jonathan Lucas

See below
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Vehicle » A L L Diagnostic Trouble Codes ( DTC ) » Testing and Inspection » P Code Charts » P1416

· P1416

CIRCUIT DESCRIPTION
An AIR pump is used on this vehicle in order to reduce the fails pipe emissions during start-up. The PCM supplies a ground to the AIR pump relay, which energizes the AIR pump.

The PCM monitors the HO2S voltages in order to diagnose the AIR system.

During the AIR test, the PCM activates the AIR pump during closed loop operation. When the AIR is activated, the PCM monitors the HO2S voltages and monitors the short-term fuel trim values for both banks of the engine. If the AIR system is operating properly, the HO2S voltages should go low, and the short term fuel trim should go high.

If the PCM determines that the HO2S voltages for both banks did not respond as expected during the tests, DTC P0410 sets. If only one sensor responded, the PCM sets either a DTC P1415 or P1416 in order to indicate on which bank the AIR system is inoperative.

CONDITIONS FOR RUNNING THE DTC

DTCs P0101, P0102, P0103, P0107, P0108, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0131-P0135, P0137, P0138, P0140, P0141, P0151-P0155, P0171-P0175, P0200, P0300, P0325, P0327, P0332, P0335, P0336, P0351-P0358, P0430, P0500, P0502, P0503, P1133, P1134, P1153, and P1154 are not set.
The engine operates for more than 30 seconds.
The engine run time is more than 20 seconds after closed loop operation.
The engine speed is more than 850 RPM.
The maximum air flow is 22 g/s.
The ECT is between -10°C (14°F)-110°C (255°F).
The IAT is between -10°C (14°F)-100°C (212°F).
The ignition voltage is more than 11.7 volts.
The engine load is less than 40 percent.
The air fuel ratio is 13.125:1.
The engine is not operating in power enrichment mode OR in deceleration fuel cut-off mode.
The short term integrators are monitored while in fuel trim cells 1, 2, 5, or 20.
CONDITIONS FOR SETTING THE DTC

When the AIR pump turns ON during closed loop operation, the HO2S voltage does not go below 222 mV for 0.9 seconds.
When the AIR pump turns ON during closed loop operation, the short term fuel trim does not change more than a predetermined value.
ACTION TAKEN WHEN THE DTC SETS

The control module illuminates the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/Failure Records.
CONDITIONS FOR CLEARING THE MIL/DTC

The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
A current DTC "Last Test Failed" clears when the diagnostic runs and passes.
A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
Use a scan tool in order to clear the MIL and the DTC.
DIAGNOSTIC AIDS

An obstruction in the exhaust manifold may restrict the amount of air flow that is necessary to affect the HO2S voltage. If you suspect this condition, remove the air pipe from the manifold and inspect the passage.
For an intermittent condition, refer to Intermittent Conditions. See: Powertrain Management\Computers and Control Systems\Testing and Inspection\Initial Inspection and Diagnostic Overview\Diagnostic Strategies\Intermittent Conditions
TEST DESCRIPTION




Steps 1-9

http://www.alldatapro.com/alldata/PR...3844/194363845