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'02 Stratus P0442 and P0172 codes


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skyfire1228
New User

Jan 23, 2015, 4:30 PM

Post #1 of 4 (2334 views)
'02 Stratus P0442 and P0172 codes Sign In

Hi! I have a 2002 Dodge Stratus, 2.4L DOHC with about 253,000 miles. The CEL is on with trouble codes P0442 (EVAP leak - small) and P0172 (fuel system rich condition); additionally, I have a very strong smell of raw gasoline on the passenger side and when the AC/heat is on.

I have a U-Scan, which has the following freeze frame data for the P0172 code (there isn't a saved freeze frame for the P0442):
Engine RPM: 1280 RPM
Calc Load: 5.5%
MAP: 8.0 "Hg
Coolant: 190 deg F
ST FTRM1: -5.5%
LT FTRM1: -25.0%
Speed: 32 mph

I've been trying to find the source of the EVAP leak for a couple months - it started out as a P0456 (very small leak) and has progressed to the P0442. I've switched out the purge valve, the two EVAP hoses that connect to the purge valve as they had a couple small cracks, and the gas cap. I haven't looked at the canister because for this model and year, the canister is on top of the gas tank and I don't currently have a safe way to drop the tank and get at the top.

I'm wondering if the two codes could be related. Could a leaking fuel injector throw a P0442? I plan on doing a fuel pressure test this weekend to see if I have a leaky injector; I've already checked to see if I have one stuck open, and all four are clicking along like they should. Is there some simpler answer I'm missing, or another test I could use to see what the cause might be?

Thanks for any advice, I appreciate it.


Discretesignals
Ultimate Carjunky / Moderator
Discretesignals profile image

Jan 23, 2015, 4:35 PM

Post #2 of 4 (2331 views)
Re: '02 Stratus P0442 and P0172 codes Sign In

You may need a smoke machine to find your evap leak.

As for the rich code, your puter is definitely compensating for a rich condition looking at your long term fuel trims. Look at the Bank 1 front O2 sensor and see if it is maxed out. Then compare it to the rear (after cat) O2 sensor voltage. If it is true rich condition the sensors should be reading rich.

If you disconnect and plug your purge solenoid's vacuum hose that goes to the engine, do your fuel trims improve?

A leaking fuel injector won't cause a P0442, but could cause a P0172.





Since we volunteer our time and knowledge, we ask for you to please follow up when a problem is resolved.

(This post was edited by Discretesignals on Jan 23, 2015, 4:36 PM)


skyfire1228
New User

Jan 28, 2015, 12:24 AM

Post #3 of 4 (2291 views)
Re: '02 Stratus P0442 and P0172 codes Sign In

Aaaah, that's what I was afraid of. Hopefully, I can get my hands on a smoke machine; there's a DIY garage not too far away, they may have one available.

I checked the O2 sensor data today. At idle with a warm engine, the upstream sensor fluctuates between 0.825 and 0.060 v while the downstream sensor stays constant at 0.765 v. I haven't checked blocking off the purge solenoid's vacuum hose yet.

I also tested fuel pressure; at idle, the needle on the gauge flickered within the range given in the Haynes manual (53 - 63 psi) for the first minute or so, then dropped to fluctuate between about 44 and 60 psi.


Discretesignals
Ultimate Carjunky / Moderator
Discretesignals profile image

Jan 28, 2015, 4:51 PM

Post #4 of 4 (2275 views)
Re: '02 Stratus P0442 and P0172 codes Sign In

If your front sensor is fluctuating, that means the sensor is responding. The PCM is at the end of adapts keeping the sensor cross counting. Higher than normal fuel pressure can cause a rich condition, but if your pressure is within specs, that should rule that out. You really need to source the fuel smell your getting. That could be a clue to your issue.

There is not very many things that could cause a rich condition. Removing the purge line and plugging off the vacuum is a good step to see if the EVAP system is causing your rich condition.

Another thing to look at is the BARO reading. Don't know where you live, but the reading should equal the atmospheric pressure where you live. Those engines are speed density, so a high MAP sensor voltage will make the PCM over fuel.





Since we volunteer our time and knowledge, we ask for you to please follow up when a problem is resolved.

(This post was edited by Discretesignals on Jan 28, 2015, 4:52 PM)






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