BayTib13

Ok, so I just got my engine running and my car on the road. I put meghan headers on it, and plugged in the O2 sensor to the bottom of the headers in the bung. I also recently had a new flex pipe made, and a bung put in it, and the O2 sensor in it. The engine had a lot..and I mean A LOT..of gummed up oil, my guess is whoever had it used some cheap oil. We used about 3 gallons of diesel and rinsed through it before we dropped it in, and pulled the oil pan and made sure it was all outta there, but im sure there's some in the motor still. Now, if I get the rpms up to about 5500 and rack em and pop it to/at 6 to 6500, I get black smoke shooting out and the exhaust smells horrible. But from idle up to 5500 it smells fine, and no smoke. My question is, what would the cause be? I'm thinkin it's just from the engine cleanin out the diesel and bad oil and the fact it hasnt been running for a long time. But I also think it may be because both of my sensors are before the cat, I can't think of why it would be doin this, since the cat is still there. Any ideas?

thanks! Sorry for the novel

Turboron_99

It shouldnt be because of the O2 placement, if it was you shoudl get a CEL and it should be like a p0422 which should be MAIN CATALYST IN-EFFICENTCY. I would drive it for a couple weeks, then change the oil again, then see where it takes you.

BayTib13

I do have a CEL, but I don't know what code it is, and I don't want to pay the mechanics around here just to put it on a computer, my dad has a friend who may have one, so if he does I'll have him grab it an i'll put it on it. For now I'll just try what you said, runnin it a couple weeks. After we cleaned it out and everything, I let it sit and then after we got it in, I filled it with Royal Purple 10-30w synthetic

Turboron_99

Go to any parts place and they always have a scanner and they will scan your code for free, It maybe that if you delete the code it might take that rich condition away. The Ecu might have the car running in saftey mode! So man just run over to an auto parts store and just play stupid, there usually pretty good about helping with that stuff!

BayTib13

haha aite, thanks for the help! I also had another question. When I start it up from cold, it idles really rough..about 900-1000 rpms..but if i give it a little gas for a minute, it idles normally at about 1400 or 1500. It also does this if I go from moving, to idling at a stop. Starts shaking cause the rpms get so low, then it levels out after a few seconds. Could this be cause the ecu as well? and would I be able to just unhook the battery to flash reset and get rid of all this?

faithofadragon

ok now GENERALLY o2 sensor wouldnt cause a condition like this with how you have it set up i had my 1st o2 on the flexpipe part of the header and my second right after the cat and didnt have any issues

black smoke = fuel

id say you arent getting enough spark or have a misfire expecially if its happening at higher rpms, check your plugs make sure you didnt crack one goin in, make sure your getting spark to that cylinder, make sure you dont have a dead hole(effed up engine) if that appears to be fine, id check the injectors out you might have a stuck open injector

i also just noticed you didnt say if you have a cat....if you dont the stuff your experiencing is sometimes normal, our cars run pretty rich as it is and the cat would burn off extra fuel so if you dont have one guess what...

do you have BOTH o2 sensors hooked up?

BayTib13

I have both O2 sensors in, the spark plugs and wires are all good, brand new. NKG wires, and plugs. I do have a cat, but both of my sensors are before it. Injectors may be the problem, they were working fine on my last engine, I just put some injector cleaner and octane boost in, gonna let it cycle through while I break it all in a little, see if that helps. Main thing is I'm wantin to figure out why my CEL is goin off. Would a door panel bein off and all the stuff on that door bein unhooked cause it? I wouldnt think so since it's pretty obvious..but never know.

faithofadragon

nope both of your o2 sensors being before the cat will turn on your CEL

first o2 sensor shouldnt be in one of the runners it should be where all 4 runners come together, if you have it in a runner its only reading the o2 of ONE cylinder

which obviously is no good

second one should be after the cat

BayTib13

Ahhh aite, the bung is at the bottom right before the flange, so that one is good, but the other one i believe is in the flex pipe, before my cat. Would this cause it to run rich or in that safe mode like you stated earlier? And could I just flash it or will i need to get the code erased?

faithofadragon

if you erase it, the code should come back, car is smart

still doesnt fix your problem though, if you dont have the first o2 sensor on one of the runners, then the ecu should be getting a good reading

first o2 sensor is the most important

second one just makes sure the cat is working

octane booster does jack sh*t btw...if it says it raises octane 3 points...it does it(if at all) like this

from 91 octane

to 91.3 octane

is the CEL flashing?