Hi, I am going to give a brief description of the problem, and am requesting some help, please.

About once a week or so, my car acts up. When "acting up", it:
1.) idles extremely rough at low rpm
2.) drops below 700 rpm
3.) Misfires occasionally when dropping low enough
4) does not move when given gas, UNLESS I hammer it (then it takes right off)
5.) CEL actually turns off (doesn't run right until turned back on.

Now, here's what I do know, and what I intend to do about it

1.) CEL for:
banki 1 sensor 1 failure
bank 2 sensor 1 failure
Pending: system 2 lean

what I want to do:
Replace both o2 sensors
Replace MAP sensor

I am hoping that is the problem. My question is:

What the heck sensor do I buy? ULEV, Except ULEV, or W/O ULEV?
it is a 2000 neon, and only one motor for that year was made, the 2.0 SOHC.

If you know of anything else it sounds like, PLEASE let me know. I am positive the decision to replace the three sensors will work, but if you have any information, I am grateful.

Oh, and a little history:
I replaced the engine with a practically brand-new one
I replaced the PVC valve
I replaced the intake gaskets and I believe the exhaust manifold gasket/s
The guy I bought it from ran it with the old motor spitting oil out the tailpipe (the entire car was coated in oil, especially the bumper

Thank you for the help

Steve

 

I really need some help with these, please!

I do NOT know what o2 sensors to get?

there are ULEV, Except ULEV, W/O ULEV, OE type, NTK OE type, VIN C... I don't know what any of this means?!?!?!

I just want to order the parts but do not know what to get?!?!??!

 

Low Emission Vehicle
Ultra Low Emission Vehicle

I use the lev's here in Texas. OEM Original Equipment Manufacturer

If it's spittin oil that far down and not burning off that catalytic converter will plug up soon or already is and will throw more emission codes

VIN codes explained here http://www.autocheck.com/consumers/c.../vin-decode.do

Lots of info here in the forums just use the search bar

 

Can a plugged cat cause both o2 sensor failure and system lean, cause the said problems, and not cause a warning for bad cat converter?

 

I had about the same problem with mine. I tried the plugs, wires, and coil pack.
Same thing, dropped to about 6-700 rpm and barely ran. Stalled a few times too, and would kick in the code for a miss on cylinder 4. Could barley get it to move unless you really stomped on the gas, and it was sucking gas like a 10 ton truck! I have a code reader, so I tried those few things and reset it each time. Never got better.

I finally took it to a shop.... unfortunately it had a blown head gasket. It was leaking between cyl. 3 and 4. It cost us a huge chunk of change. Thank goodness for Mom! Of course we have to sign over out tax return..

But it runs fine now...

 

Okay, so I replaced BOTH 02 sensors last week, and am now throwing codes p0134 and p0140. The car runs smoother, but it still experiences a rough idle almost ALL the time now. I experience all the same symptoms, and I don't know what to do now. Electrical problem maybe? Bad cat converter?

Please, help me :/

 

Impossible. I bought a used motor with 55k on it, and had my friend, who is a master mechanic, perform the swap. The motor is beautiful and clean.

 

use the idle ajustment screw...
on the thottle body. its a bumb stop screw

 

Good idea, except it is NOT an idle problem, it is definitely either an exhaust of fuel problem. Both BRAND NEW o2 sensors are completely failing, and the codes are p0134 and p0140, which is both "stuck at center". I'd appreciate it if I was not mislead by someones opinion, I want facts here, and I know there is a problem that has absolutely NOTHING to do with a little screw you're talking about. Sorry, but I am sick of being misguided.

Somebody with some LEGITIMATE advice, please help. Why are both of my o2 sensors failing, and why does the car idle rough, often times idling at or around 600 rpm?

Here's some other things that happen: When I pump the breaks, the rpms rise to 1000, then fall to 500, both o2 sensors were replaced, and the car runs like a beauty outside of the rough idle, only since the sensors were replaced.
I am positive it is either: clogged Cat, wiring problems, bad PCM, or MAP sensors. I don't know. I cannot figure this out, and I need to figure it out.

 

Any ideas or advice?