I have a 2004 civic ex 1.7l v-tech and my check engine light just came on and i noticed several times on the high way my car will buck for a split second.Had my ecu read and the auto parts store told me they have never seen a code like this ever.If any one can help lemme know....ill post the reading they gave me.


P2646
Rocker Armactuator
A-Bank 1 PERF
Stuck Off


P0134
025 CKT NO ACTIVITY Detected 1/1

 

A quick google search reveals the p2646 typically being related to a faulty VTEC Oil Pressure Switch. Check your oil level, any and all connectors to that switch, as well as the switch itself.

For the second code, please read this: http://www.obd-codes.com/p0134

 

First off, whenever you have two or more codes, reset the ECU and test drive until the CEL comes on again. Then scan to see which code reoccurred. One of the codes may be old from a problem that no longer exists.

The VTEC system works off of oil pressure. When the ECU tries to engage VTEC, it will turn on the solenoid valve then check the switch to make sure that the pressure to the VTEC mechanism is indeed high enough for proper operation. If the proper response from the switch is not received, the ECU will bail out of trying VTEC, set the code and turn the CEL on. For the rest of the drive, the rpm will be software limited to about 5000 and the VTEC will not engage.

Also you could take the VTEC valve off and check the screen may be blocked with oil sludge.