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OBD_II Scan code P1340?? What is it?

05-05-2004, 02:24 PM
2000 Isuzu Rodeo, 3.2, 112,000 miles, Service Engine Soon light is on, won't pass inspection till I get it cleared off. Hooked up a scan tool the only code is P1340 and it scan tool says it's a Manufacturer Specific Powertrain Trouble Code. Not listed in Haynes manual.

Cleared the code with the scan tool and it came back within the same day about an hour later. Anyone have a reference to what code P1340 is? Something I can look into myself? What repairs need to happen? Estimated Costs?

05-05-2004, 03:51 PM
have you recently changed your plugs?
Only use: Denso K16PR-P11 spark plugs others can cause missfire codes. See my FAQ link in my sig below for more general maintainance

If you have a 2000-2004 Isuzu, make sure you only use Denso K16PR-P11 spark plugs. The 2000-2004 engines have the GM/delphi "ion sensing" ignition system where the spark plugs are used as a sensor (when they are not firing) to measure the electrical resistance of the gasses in the combustion chamber. Other plugs may cause the ECU to register a code (misfire code: P1340). Also, it has been noted that some 00 trucks came with champion plugs from the factory, which cause knocking, due to to ion sense coils.

If you have 1998-1999, the suggested plugs are NGK or Denso or Champion double platinum plugs.

A dirty EGR port may cause knocking. Knocking also, may be caused by carbon build-up in the combustion chamber. Adding one 20oz bottle of Chevron Techron Concentrate® every 3k, will help to keep the combustion chamber and fuel injectors clean.

Finally keep that PCV valve clean! Either replace it once a year, or pull it every 6 months or so and spray it out with some carb cleaner.

05-05-2004, 04:12 PM
As a matter of fact, I did change the plugs a while back, don't remember the brand or number, probably used something cheaper than the recommended. Do remember will the rear coil/boot assembly. Was stuck to the plug and tore in two on removal. Do they sell only the boot? Why no they don't. Had to buy a whole coil/boot assembly, at the dealer no less.

Did change the PCV last night and also pulled and cleaned the EGR. There was only expected light carbon deposit on the EGR.

Thanks for your response, very much appreciated! I'll change the plugs today.

05-08-2004, 02:43 PM
A quick update and thankyou....
Had to go to the dealer to get the plugs, only found one parts place the carried Denso and didn't carry that one. At the dealer the plugs were $14.10 each. BUT, after changing the plugs and clearing the code, not only did the code stay cleared, but the performance improved.

Lesson learned, and thanks again!

05-09-2004, 09:09 PM
see there sometimes it does cost more for aftermarket parts

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