rpm limit

[rrickard]

Hi, how's everyone?
I have a 2001 Impala 3.8. My problem is when the engine gets to around 3000rpm, it starts to spit and miss-fire. The check-engine lite is on at all times. I have'nt really done anything yet(wife's car) What do you think.
Thanks RCR

[BNaylor]

Best thing to do is get it scanned and see what odb-ii DTC error codes are causing the SES/CEL light to come on.

[tractorboy]

I always thought that for OBDII the check engine light just meant the gas cap was off AND if there were trouble codes that the MIL light would be on ?

[BNaylor]

Originally Posted by tractorboy

I always thought that for OBDII the check engine light just meant the gas cap was off AND if there were trouble codes that the MIL light would be on ?

Its more than that. All OBD2 means is On-Board Diagnostics II. There are a bunch of odb-ii codes related to emissions and engine controls not just gas cap which is in the evaporative emissions group of codes.

The service engine soon light (SES) or check engine light (CEL) is the malfunction indicator lamp. (MIL).

The actual fault code generated and read with a scanner is called a DTC or Diagnostic Trouble Code.

[tractorboy]

there is both a check engine light and the mil lamp ?
my understanding of the the check engine lamp was, on my obd1 car, short two of the terminals together on the ALDL and count the blinks for the trouble codes. On obd2 , the check engine light was just associated with the gas cap . Try it remove your gas cap and drive your car, the check engine light will come on and the MIL light will not, then put the cap back on and the check engine light will go out after a few blocks. OBD2 the mil light illuminates when there is a DTC or trouble code.

[BNaylor]

Originally Posted by tractorboy

there is both a check engine light and the mil lamp ?
my understanding of the the check engine lamp was, on my obd1 car, short two of the terminals together on the ALDL and count the blinks for the trouble codes. On obd2 , the check engine light was just associated with the gas cap . Try it remove your gas cap and drive your car, the check engine light will come on and the MIL light will not, then put the cap back on and the check engine light will go out after a few blocks. OBD2 the mil light illuminates when there is a DTC or trouble code.

Odb-i and odb-ii standards are different to include getting the CEL light and retrieving codes. Also it depends on the year, make, and model of the car. In this case this Impala has an odb-ii Series II 3800 V6 engine. There are numerous odb-ii DTC error codes. Odb-ii Scanners will have these codes programmed in along with a booklet. Also, the codes are listed in the respective GM service manual.

All that needs to be done with a scanner is to hook it up to the port under the steering column, press read and off it goes. No jumpers are required. Also the scanner will reset the SES/CEL light with a reset button after repairs have been accomplished.

When the gas cap is removed on this particular car, a DTC of either P0440 or P0442 will normally store and then trigger the SES/CEL light which is the MIL light. They are one and the same. Also, most GM "W" body cars have a Service Vehicle Soon Light (SVS) which are not odb-ii related codes.

[tractorboy]

Yes , a scan tool is needed for obd2 . Ok the service engine soon lamp, that is the one tied to the gas cap.

[abaird]

Service engine soon, mil, cel, they are all the same, it depends on the manufacturer. OBDI is relatively simple compared to OBDII. And yes, as stated before a loose gas cap will trigger the light, but so will one of a thousand things associated with the OBDII system.