Hey everyone, after a new tune and some pulls, my car threw these two codes:

P1114
P0134

From what I read, the issue is with driver side pre-cat o2 sensor. Before I go out and replace both of my o2 sensors, can anyone confirm I'm on the right track?

The car stutters much more then it ever did before. Car has 40k miles, but I been suspecting that it needs new plugs and coils. During hard pulls on my old tune, the car would sometimes break up. I'm guessing bad plugs/coils fouled up the o2 sensor?

My plan is to replace both pre-cat o2 sensors and do plugs/coils. Plugs and coild have been sitting in my garage for over a month, just didn't have time yet.

Side question, Bosch FR-6 plugs should be gapped to .028? Correct?

 

if the car "broke up" before and still does after a tune then the plugs and coils are the most logical and probably necessary place to start. even if that wasn't causing it, swapping these out esp after a new tune is never a mistake. yes, to 027/028 gap.. perfect for the bosch fr6.

lastly depending upon how old the 02's are they too might well need replacing though i myself would begin with the plugs/coils you are on the right track with the p0134 and a bad pre-cat. would not be uncommon at all esp to appear after some mods. i needed to swap mine cpl years back when i went decat. cheap parts = good.

 

Not to put too fine a point on it but if you did a "tune" and didn't renew the plugs and for good measure the coils, shame on you.

P1114 - Heating LSU, inertia fuel shutoff -- signal implausible.

Possible fault causes:
Open circuit.
Oxygen sensor.
DME control module.

Far more O2 sensors go bad than DME control modules so my money's on the sensor.

P0134 - Oxygen sensor ahead of the TWC, bank 1, -- open circuit.

Possible fault causes:
Oxygen sensors [sic] (heating connection)

I forget the O2 sensor error code my Turbo's O2 sensors, well, one of them anyhow, but a #1 sensor, triggered back in Jan. of 2015 but as soon as I got home I got the car in and had all 4 sensors replaced. The car had 132K miles on it and the sensors were original.

The tech said the old sensors looked "ok" but the car ran noticeably better after the new sensors were installed. The #1 sensors are wide band to ensure more precise fueling -- turbo-charged engines are pretty demanding when it comes to fueling -- and I believe I got my money's worth out of the sensors.

Might mention more recently I had the coils replaced and the plugs replaced. The coils were original and suspected of being the cause of some misfires upon cold start. The plugs were not due but the tech suggested that since he was there and the plugs were due in another 10K miles might as well, and I agreed.

The engine ran a bit better afterwards but the improvement was not as pronounced as after the sensors were replaced.

My advice would be to replace the plugs and coils. I do not know what plugs to recommend since you have a tune. What does the company that sells the tune advise?

Also, since the car is tuned I'd replace all 4 O2 sensors.

You can run a bottle or two of Techron -- as per directions -- through the engine. The general rule is if the engine runs better after one bottle to repeat the treatment with a 2nd bottle. I like to do this before an oil change is due.

Might add that the new plugs and coils did not cure the misfires. The tech believes the problem is a couple of "sticky" when cold injectors. The engine never misfires other than just moments after a cold start and never manifests any signs of any other issues. Next time the car is due for an oil/filter service I'll ask the tech what suggestions he has for the misfires.

 

Might add that the new plugs and coils did not cure the misfires. The tech believes the problem is a couple of "sticky" when cold injectors. The engine never misfires other than just moments after a cold start and never manifests any signs of any other issues. Next time the car is due for an oil/filter service I'll ask the tech what suggestions he has for the misfires.[/QUOTE]


above issue if misfire only at cold engine ..check engine temp sensor

check with durametric ....cold engine ambient temp and engine DME temp sensor should indicate near the same..

 

Coincidental or a result of the tune?

I'd certainly run this by who did the tune. I'm assuming you are referring to a tune as modding the ECU/ECM for enhanced performance? It's possible your new tune is the culprit and it's a software issue not a mechanical/ electrical problem.

 

above issue if misfire only at cold engine ..check engine temp sensor

check with durametric ....cold engine ambient temp and engine DME temp sensor should indicate near the same..[/QUOTE]

Checked already. No significant differences between coolant temperature cold, intake air temperature cold, and ambient at engine start or any other time.

As tech offered and as I posted above, probably just a couple of sticky injectors. It is the same 2 cylinders that misfire every time, too, which does suggest the problem is confined to the injectors of those cylinders.

 

Original tune was crap, which I assumed was the reason why the car ran like it did and broke up once in a while under heavy load. I now went with Cobb V2 tune and will later fine tune it.

Back to my issue. I just replaced coil, plugs, and both o2 sensors. Car barely idles... I made sure I double checked that I correctly plugged in the coil connectors till it "clicked" but guess I missed one. New codes are p0300 and p0306. So the coil closest to the passenger seat (6th cylinder) is misfiring?

Guess I need to take it all apart tomorrow and reseat the 6th cylinder coil?

 

Yes you need to go back in and "reseat" the #6 coil.

I hope this proves to be the sole cause of the engine's behavior.

I'm a little worried when I read that you have done a new/different tune and will fine tune the new tune.

I would have been inclined to revert back to the stock tune -- if this is at all possible -- and get the engine running properly then gone with a custom tune and at the same time fine tuned the custom tune.

 

So it ended up that I just didn't connect coil #6 all the way in. Car starts and idles fine now. I wasn't able to drive it anywhere yet but I'm hoping after new plugs, coils, and both pre-cat o2 sensors I won't get the o2 CEL anymore. Should see tomorrow after I put some miles on it.

Now I just need to find the dam boost leak I have right behind my oil filter. Been fighting with that one for over a month.

I went with Cobb Access port V2 tune. Once Cobb brings back the self tuning software to regular users, I'll fine tune it myself. The car just had an unknown tune and boost levels were all over. Car has 40k miles and previous owner already did the plugs so I had no real reason to do it again before I flashed Cobb. My car did stutter once in a while at peak boost but I figured it was the tune since it was spiking very high boost levels.