I have the p1400 code along with the P0365 code??

SOURCE: 2009 CHEV AVALANCHE DTC P1400

p1400 is a egr valve malfunction which will cause misfire

Romel Edmondson

• 68 Answers
• Posted on Feb 14, 2009

SOURCE: 2000 CIVIC System too lean Cylinder 3 and 4 misfire Deteced

1. P0171: This means that the oxygen sensor has detected a lean air-fuel ratio. This can be caused due to a vaccuum leak or a problem in the HO2S circuit or the HO2S (Heated Oxygen Sensor) itself. (Bank one Sensor one). This is commonly located along the exhaust pipe. It could also be a bad Mass Air Flow sensor or a bad Engine Coolant Temperature sensor. Diagnostic checks will be needed to be carried out to be verified though
2. Well as for the other codes, it means #3&4 cylinders are misfiring. It is a possibility that the P0171 code mite have caused the others to show up. I can be wrong though. But it is a strong possibility. If the air fuel mixtue is too lean indeed, mis-firing will occur, unless it is an actual electronic and not a mechnical problem. By the way, when these codes appear, how is the engine's performance. Does it remain the same or behaves poorly?

Joe Lamb

• 463 Answers
• Posted on Apr 02, 2009

SOURCE: P0300 and P0352 in a 1996 dodge caravan

Check all plugs and wires..If they are grounding out it will make it miss.Also check for vacuum leaks..Hope this helps you..Have a great day..

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SOURCE: engine misfire code multiple cylinders, starts

There are quite a few things that can cause this.
Check your fuel pressure to start. 55 psi key on is good.
Also make sure it dosen't fall back down should hold at that psi with out engine running.
Aslo the intake's like to leak air around the gaskits which will cause a miss fire.
Aslo the mass air flow.

Ryan Lutton

• 1267 Answers
• Posted on Mar 25, 2011

SOURCE: 2003 Chevrolet Trailblazer 4.2L I6

With a service engine light blinking...don't drive it.

When replacing the spark plugs, double check that the boots on the coils are installed correctly. Check these again, and make sure to either listen for or feel a little click which tells you it's properly seated on the top of the spark plug. This is a common thing, happens all the time to people with TB's and Envoys. I've even done this myself.

In case you didn't know, # 1 cylinder is up front near the fan, then it runs in order to #6 at the firewall. Possibility....(don't take this as doubting you), maybe the wrong coil was replaced and one or more coil boots weren't set properly? Some things to check anyway.