p0172 - 1/1 af rich

kc2005ptgt · Post by **kc2005ptgt** » Mon Mar 31, 2008 10:36 am

Got this code today after filling up. i have no cat, a lth, comp 400 cam, udp, 60mm tb, and cai. does this mean the upstream o2 is bad? i have been running this setup for about 15k miles. car has 89k miles, original o2. Any help?

Panhead · Post by **Panhead** » Mon Mar 31, 2008 10:51 am

how many miles on the car? if its the original o2 sensor, its whats causing for the code. your o2 sensor is dead.

kc2005ptgt · Post by **kc2005ptgt** » Mon Mar 31, 2008 1:18 pm

89000 miles. is there a way to test the o2? this bites.

Panhead · Post by **Panhead** » Mon Mar 31, 2008 2:16 pm

kc2002acr wrote:89000 miles. is there a way to test the o2? this bites.

i checked my manual and it doesnt tell you how to check it out.

kc2005ptgt · Post by **kc2005ptgt** » Mon Mar 31, 2008 4:16 pm

Boooo... I checked my FSM I have, but it is for a 2000 m/y neon, and I did not get anything as well. Anyway, I am going to check the plugs and take a pic and maybe someone can look at those and say "hell yeah your running lean, or rich, or whatever..."

I just need a way to tune it (insert megasquirt plug here).

MyNeonSaysHi · Post by **MyNeonSaysHi** » Mon Mar 31, 2008 4:21 pm

Yeah dude, start with the simple stuff first. I am guessing your plug fouled out.

kc2005ptgt · Post by **kc2005ptgt** » Mon Mar 31, 2008 4:27 pm

P0172(M) 1/1 Fuel System Rich A rich air/fuel mixture has been indicated by an abnormally lean correction factor.

There is the code, btw, for anyone else wanting to chime in and make some suggestions. My wife is going to kill me... it is always something with this car, nickle and diming us to death

Thank god the engine is still holding up well :crosses fingers:

btw: rich is A/F < 14.6, correct? Meaning less parts fo air to fuel, so my air-> 14.6/1 <-fuel... lower than 14.6 means less air to 1 part of fuel? Or a RICH on fuel mixture..?

quicksilvr · Post by **quicksilvr** » Mon Mar 31, 2008 11:35 pm

Replace your O2. Now. Before you gunk everything up and get 11mpg like I did.

It's the same code I got. I replaced the O2 and it fixed it.

You can also just unscrew the O2, and blow it off with an air compressor and then wipe it down with a dry rag. Don't use any cleaner on it. It might just be gunked up and will work fine if you clean it off. Or at least buy you time until you have to actually get a new one.

03blackrt · Post by **03blackrt** » Mon Mar 31, 2008 11:45 pm

kc2002acr wrote: btw: rich is A/F < 14.6, correct? Meaning less parts fo air to fuel, so my air-> 14.6/1 <-fuel... lower than 14.6 means less air to 1 part of fuel? Or a RICH on fuel mixture..?

Correct!

kc2005ptgt · Post by **kc2005ptgt** » Tue Apr 01, 2008 10:37 am

Ok, so code went away... no wonder guys give their cars a girls name. This thing is as sensitive and as picky as a woman! I am going to replace the plugs and clean the o2 sensor. Dave, where did you get your o2, and how much did it cost?

kc2005ptgt · Post by **kc2005ptgt** » Wed Apr 02, 2008 4:05 pm

Ok, so I changed the plugs and cleaned the O2 with a clean rag and I took some pics... Can anyone tell by looking at the plugs or O2 if it is running rich or lean, or maybe something else would be wrong? Anyway, here are pics...

This is the O2 sensor (upstream)

These are the plugs from Left to Right, 1, 2, 3, 4

spencersummerfield · Post by **spencersummerfield** » Mon May 26, 2008 4:11 pm

I have the same code.... is your sensor in the first 02 hole in the header or down i the collector.????

I can clear mine by resetting the computer and I get about 100Miles before it kicks back on...

I cant figure it out... mine is in the first header hole off cylinder #4 .

could my sparkplug gap be too big?

the 02 is brand new. I am goona try plugs. I have them gapped at .040

Wenuden · Post by **Wenuden** » Mon May 26, 2008 5:29 pm

the plugs look pretty good. Black is rich, ashy is lean. Yours look fine.

BlackRoseRacing · Post by **BlackRoseRacing** » Wed May 28, 2008 6:52 am

The electrode on cylinder #1 looks like its running a little rich....
Replace the plugs with a cheap replacement until you figure out the problem. No I am not going to ask what brand you currently have since you aparently don't want people to know because of the tape

If you get a replacement O2 senesor, NGK and Denso make them for Chrysler, don't grab a Bosch since we see them fail all the time at work. As for testing an O2 sensor, there is a way to do it with 12volts,multimeter,propane torch, but it will not test reaction time correctly so since you already have the 1/1 code, I'd say replace the O2....
The cylinder #1 richness, I'd say its from a dirty injector since that's were all the sediment in the rail settles and cyl#1 is commonly the cylinder to cause misfire problems.....

kc2005ptgt · Post by **kc2005ptgt** » Wed May 28, 2008 12:05 pm

You're funny, the tape was for me so I could remember which plug was 1, 2, 3, and 4

I run NGK V-Power's.

I was unaware that we could run aftermarket O2 sensors in our cars, that's a great thing! Funny, almost everytime I get the P0300 codes, it is P0301 or P0302.

Usually from the UR UDP though, but something I should look into while redoing the head and bottom end this summer.

Thanks guys!