MudBggn

Recently just got this code. "VTEC system malfunction"

Resetted it and it came back.

Before, the car would throw P0133 and I would just erase it and it will never go back. Only time it goes back is if I unplug the battery. I would just erase it again and it never comes back.

Then it started throwing it again and erasing it doesn't help anymore. I replaced my bank 1 o2 sensor and the code went away. Then after replacing that, P1259 came up and it's the first time.

Car has the original B16 with CAI and header.
Car seems to run fine. I can get it up to 8k rpms with no problems and I hear my vtec. Even with the CEL on, the car runs flawlessly.
It doesn't bog or hesitate.
Engine is not low on oil. It does burn oil though and I would just check it regularly and top it off a little when needed.
Vtec solenoid is clean. The screen is not clogged. Connectors has voltage and continuity.
All wires are good.

Only weird thing the car does is when I stop at a red light or something and put it in neutral, the rpms would hang at around ~1200 for about 3 seconds and it goes down to normal idle 500~750. And no, A/C is not on.

No vacuum leak. Throttle body and IACV are clean.

Also followed the service manual on how to check the solenoid and pressure switch but the code keeps coming back.

How do I fix this problem??

Former User

You did ALL the service manual electrical tests for P1259?

MudBggn

Yes. Even replaced the ecu with stock one from another em1 when I didn't even had to. Took the whole assembly out and everything is fine. Code came back.

Former User

Have you measured the oil pressure?

HondaPartsHero

http://www.justanswer.com/honda/18ar...nda-civic.html

MudBggn

Yea, I spent about $200 on the gauge just to test the oil pressure.

HondaPartsHero, that's what I did. I have that manual in pdf.

I'm stumped. Code is back on.

90efb16

iTrader: (7)

THIS ^^^^^ is great infomation!!!

HondaPartsHero

What's the history of the car? Are the original owner?

MudBggn

I'm the second owner. Car has 95k miles. Car is well maintained and runs smooth but this code keeps coming back.

Is there anything else I should check?

I'm about to go to Honda and buy the solenoid and pressure switch and see what happens. If it comes back, then I'm out another $200.

HondaPartsHero

You could bypass the switch and see if the code comes back and further clarify before you buy. Similar to this but use a OBD2b diagram

MudBggn

I was hoping I wouldn't have to try that. ughhh

so its B12 and C10 for this?
http://www.ff-squad.com/technet/wiring.obd2b.htm

MudBggn

Had to drive it for about 100 miles for everything to be "Complete" (damn evap) and the code never came back on. Also cleaned the iacv again and it fixed the idling issue.

Thanks for the help.