31L/100 km mileage
 

Hi - so the engine is in the car now and it's running, but the mileage is 31 L per 100 km, which means something is really wrong.

A few possibilities:

O2 sensor
Air leak in manifold
MAF or MAP sensor

Any suggestions? Any checks you can suggest?

Thanks, O6B

Gonna start with the basics, do you have any codes?

I'm on the mobile app so I dont see sigs what cobalt/g5 do you have?

The gas mileage showing in the display is now showing the right mileage about 7-8 L/100 Km.

Scan it. We can't help you but obviously something's wrong

Yes when I shift gears, the throttle stays open and high - I'll scan it in the morning and post it - it'll be easier with daylight. Thanks for the hand.

Code scan p0068 p0106 p106P p0480. I'll check for vacuum leaks now.

Engine power reduced message appears at startup. Disconnected MAF and car stopped so MAF may be ok, swapped in a new air filter and another MAF - same problems at startup (rev 2500 rpm) then it went down to normal 900 or so. Cleared the codes and it seems to be fine now. Will it return who knows. Yes just took it for a drive and 480 and 106 codes appeared. I might have to rethink a long trip tomorrow I don't want to damage anything.

bump


Replaced MAF and still the RPM rises in between shifts.

Codes 480 and 833 - Any ideas?

:cssNET:

Here's a solution path from website http://ricksfreeautorepairadvice.com/p0480-cobalt-fix/Fix code P0480 on Cobalt

This vehicle has a 2-speed cooling fan. If you run into the P0480 code and find that the fan will only run on the highest speed, start by checking for a blown cooling fan fuse #1 in the underhood fuse block. If that’s ok, swap cooling fan relay #1 with the high speed cooling fan relay #2. Both relays have the same part number.

Rest the PCM to clear the trouble code and drive the vehicle. If the low speed relay is bad, the swap will result in a new code, P0481. That will confirm that the relay is bad. Replace the low speed relay.

However, if the P0480 returns with the relays in their swapped positions, check the wiring harness for an open condition. Check the continuity of the dark green wire from the #1 cooling fan relay to the PCM, pin #47

© 2012 Rick Muscoplat
Source 480 Code solution

So I did the swap and 480 returned, so now I'll inspect the green wire to PCM pin #47