Anyone knows what this PO 1399 code is on a DC2 P72 ECU?
I searched but could not find it. I had the head machined and reinstalled it and immediately the car was misfiring on all 4 with the 300-304 codes. I checked all the plug wires, removed and verified position of Dizzy, checked engine timing marks, double checked all connections and vacuum lines and nothing...I erased the codes and restarted the car but still misfires but no CELs this time...timing marks are correct. It has new plugs, new fuel filter, new air filter, new plug wires, new dizzy, new timing belt, water pump, new oil, thermostat, PCV valve, etc. The car dies once it reaches operating temperature, the idle goes too low and dies off. I had cleaned the IACV and TB and installed new TB gasket and intake gasket.

 

Only thing I can find similar to the code you posted is this

P0139 Secondary Heated Oxygen Sensor (Secondary HO2S) Slow Response

I dont know if you added too many 9's to your number or not but I looked in the Integra Faq and couldnt find your posted error code. Looked in my Chiltons book and none either

 

Yup, I checked the manual also but the 1399 is not listed, I had 6 codes and that was the last one on my scan tool...the secondary O2 sensor is brand new, a denso OEM unit. I do not think that would be the issue.

 

Did you bleed your coolant system?

 

I filled with fresh coolant but did not get the car to operating temp toi bleed since I had the misfires and codes...

 

So what were the other codes?

 

PO 300, 301, 302, 303, 304. I stopped the engine,rechecked all vacuum lines, dizzy position, timing marks, plug wires and then erased the codes and restarted the engine. All codes were gone except the 1399. I am thinking maybe the gas in the tank is the culprit since the car was parked by previous owner for over 6 months with 1/4 of a tank maybe the gas went bad(?) and is causing the issues? I can't find anything wrong otherwise but it still idles shaky and dies off.

 

You should get the old gas out and add new fuel to it. That could be an issue as well

 

It does not smell right either, as if the fuel is not burning right, I am draining that old fuel and hopefully with new fuel the issues will go away. It starts right up each time and I cannot find anything wrong otherwise.

 

Well, I drained the old fuel and put fresh super in the tank but still have the misfire in all cylinders...codes 301 thru 304. I checked timing marks, electrical connectors, vacuum lines, spark plug wires, everything looks fine. The plugs are new and so is the dizzy, fuel filter, air filter, the head was checked and resurfaced and I used a new HG torqued to specs...not sure what the problem is. Car tends to idle way too low once it warms up and dies. I put new coolant and thermostat and bled the system. I checked the idle screw on the TB and it did not make a difference adjusting that. I had removed the TB and IACV and cleaned both, it has a new TB gasket. Also has a new IM gasket. Valves were adjusted to spec and it has new timing belt. I am truly at a loss as to why it's doing this unless the new dizzy is bad, or there is an issue with the block I am not sure what the issue is. Any ideas??

 

1399 is a random misfire code. i have it and my valves are bent.

 

oh dang I hope that is not my problem...how did you bend your valves?

 

I am having a mechanic friend of mine look at it. He does not think it would be a bent valve because I am getting the misfire in all cylinders not just one. I am thinking it might be the dizzy although it was new...or an issue with the temp sensor

 

thats what I was told from the local perf. shop. i pulled my rail and moved the injectors around and no more CEL. I guess the Honda Gods have shown down on me once again.

 

Know this sound dumb but you positive your wires are in the correct position?


Also where did you get the distributor? Is your rotor and cap new as well??

And correct because its in all 4 cylinders I wouldn't assume its a bent valve its most likely somethin to do with the ignition.

Id swap the ecu for ***** n giggles as well

 

po1399 is a misfire. this happen when the ignition system is wet or about to go. or there a short in the lines.. this has to do with spark only... basic test is start with fuses/links, connectors, cables/wires, most of the cars i work on with this code on is because the engine bay was washed and there a few device still wet please let me know year model engine size and ill look it up.

 

Just replied to a 6 yo thread, awesome...