artbran

iTrader: (2)

So just saw my Check engine light flash for about 10 seconds. Got me a little worried and when i checked the codes, it says that its a misfire on more than 1 cylinder. The best part is that this just happen after driving 20 miles after filling up. So i'm thinking that the gas that i used is not the greatest.


What do you guys think?

artbran

iTrader: (2)

Oh and i will add that it was premium.

So do you think its the gas or something a bit more involved?

GreenMonster

You're the guy with no cat and some kinda 02 sensor replacement thingamajig, eh ??

Bad cats will throw misfire codes... do a search here for catalytic or misfire*

edit: a search for P1399 Turns up some other interesting threads:

https://acurazine.com/forums/showthr...ighlight=P1399

REDLINEN

Well I would say that the back 02 is picking up a high Hc level witch is telling the PCM misfire so put the cat in the equation and it will lower the HC levels like it intended to do and bang no more codes. But what would I know im only a technician......

artbran

iTrader: (2)

alrighty then... will do

REDLINEN

I was just thinking about this after I got a lil more sleep and came up with another possible senario that sounds a lil more correct to me. If you have the 02 trick on this car there is your problem right there. The 02 trick is sending the Pcm false readings and the pcm is tunning the air/fuel mixture of thoose readings. Now in most casses this will work fine but in some this will give a reading that will make the mixture lean or rich at any time when it might want the opposite or neither. When we get a real rich mixture you could be having a rich misfire, On the other hand you could have the trick sending a signal saying lean when the engine really needs rich and then you have a lean misfire. Now the flashing indicates shut the engine down, It does this when ever the engine has bad misfire's or pre-ignition and also when we have detonation to prevent internal damage. I suggest very strongly when you have something that send signals to your Pcm dont want it send trick or false signals. You are not creating more horsepower but only loosing it due to the fact that the engine will not run the way it was intended. cutting the cat out only raises emissions if you think it is restricting you buy a high-flow cat. And the only way you would ever need to not have a cat because it is restricting you is when you get in the 1000hp range and looks like your are far away from that. Hope I could help any other questions please ask.

artbran

iTrader: (2)

^

See the thing is that i have been checking my codes every 2-3 days or so after i put in the sim. And why i thought that the fuel could be the problem is that after 600 miles, driving with it in (a road trip), and only filling up at Sunoco, Hess or Wawa, i never had anything like it. Then i fill up at Exxon and bam 20 miles later i get a flashing CEL, when earier that day, it didnt show anything on the reader. It was clean (after the install, it didnt show anything once i might add).

I have noticed that after driving 20 miles with emission system being faulty it triggers the CEL. So thats where my reasoning came from. I'll drain this gas and fill up with some good shit at Wawa, Hess or Sunoco and I'll read the codes again. And if another 1/4 tank shows this same thing, then I'm getting a HF Cat on Monday. And if not, then i'm going to get a cat sometime within the next month or so.

REDLINEN

Yeah, I see what you mean but believe me I know a lil something im not talking out of my ass. There is no reason you should even wanna run without a cat. You are gaining nothing. You are loosing HP beleive me.

ThinJim

iTrader: (3)

I've always wondered about the science behind the secondary o2. I have an o2 sim with the cat removed. I read where some say the secondary is useless, you just pull it out and let it hang. I don't see this happening sucessfully.

Let me get this straight.. the 1st sensor reads how rich or lean the motor is running and sends a signal to the pcm and it makes the adjustments. at the same time, the secondary reads how well the cat is doing and making sure the primary 02 is doing it's job, (not to rich, not to lean)?. the signal that the secondary sends to the pcm, does this signal alter the fuel deliverery? My secondary o2 is plugged into the exhaust pipe in about the same placement as where it was with the cat, the o2sim just alters that signal by supposedly steadying the voltage to the pcm.

I have many mods on my car, and it usually takes about 2 weeks for the light to come on, I checked it a few times in the beginning, and it was the same misfire code, got tired of seeing what the code was and just reset the pcm by removing the fuse for a min.

If you could share some more info, that'd be great as I'd like to have a better understanding. cheers

REDLINEN

That is the job of the Second o2 to see if the cat is doing its job. It also helps the pcm fine tune the air fuel mixture. When both o2 sensors are online and working this is called close loop thats when the pcm has all the info it needs to fine tune the air/fuel mixture. When there is a false signal or none going to the pcm it has ussually will run rich because the pcm will think the car is cold and in open loop so it runs rich to help with the warm up process. If there is a false signal telling the wrong info to the pcm this could also cause it too run lean. either way you never wanna trick the pcm. I hope I helped you awnser your question. In short the second Pcm is just monitering the cat to make sure its doing its job by cleaning the emmisions that the engine puts out but it also helps with fine tunning the engine by telling if the engine is misfiring due to a lean or rich mixture. False info to the Pcm is very bad unless you have done tons of research.........

Sun Diego CL-S

were you able to resolve the problem, Artur?

artbran

iTrader: (2)

I drained the fuel (i needed gas for my lawnmower and pressure washer anyway...) and filled up with fuel from Hess, and then checked the codes again and again. There is nothing how. I'm going to be getting a cat in the near future, but as for now, everything seems fine. I think that i got a bad batch of fuel which fucked with my computer and some other stuff. I'll post again if something happens.

seafoam comes next!

Type S Zero

this week i had one at work caused by a bad EGR valve
misfire lights up CEL instantly, but EGR malfunction will take 2 consecutive driving cycles before lighting up CEL.

could also be clogged passage between intake and EGR valve

so your seafoam is a good idea

artbran

iTrader: (2)

I filled up with 94 octane Sunoco gas and no more code. I checked them every day since i filled up and nothing. So it had to of been the shitty gas. I think that that exxon station didnt even add the additives that they need to to make it premium.

cubaknow

wassup guys i need a techs help my car is throwing cel everytime i drive hard and then it when i turn off the car and then later on try to turn it on and it idles real rough feels like the whole engine is rocking shaking like crazy then i get check engine and tcs light . then the tcs light turns off and it take a while for the car to turn over. took it too the tech changed the plugs and coils and still same then 2 weeks later. took it back and the car had a super rough start and start shooting smoke out the exhaust i dont know what else to do and it threw the code also p1399 guys help me pleaseee i need it tell me what to do.