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P0172 Diagnostic Guide for 2000 Dodge Stratus 2.5L - Rich Fuel Condition Troubleshooting

Model: 2000 dodge stratus 2.5l Fault Code: P0172 Posted: 2018-07-04 03:44

Fuelsys1 CL Fuelsys2 --? Loa--pct% 20.0 Ect(°c) 88 Shrtft1(%) -7.8 Longft1(%) -25.0 Map(kpa) 37 Rpm(rpm) 3200 Vss(km/h) 138 ? I've been experiencing a persistent P0172 code on my 2000 Dodge Stratus 2.5L for some time now. I've already cleaned the EGR valve and replaced all cracked hoses, but the code remains unresolved. I'm at a loss as to what's causing this rich fuel condition. Any insights or diagnostic steps would be greatly appreciated. The P0172 code indicates an engine running too rich—excess fuel in the combustion chamber. Common causes include leaking fuel injectors, faulty fuel pressure regulator, contaminated intake air temperature (IAT) sensor, or a malfunctioning oxygen (O2) sensor sending incorrect data to the PCM.

Related fault codes
P0172
Comments (6)
Anonymous 2018-07-04 07:20

P0172 is a rich condition code. Likely causes include leaking fuel injectors, high fuel pressure, or a faulty fuel pressure regulator. The PCM adjusts fuel trim based on oxygen sensor input and may interpret excess fuel as a rich mixture.

Anonymous 2018-07-04 07:41

Check your fuel pressure with a gauge. Remove the vacuum hose from the fuel pressure regulator and run the engine for several minutes—fuel leaking from the regulator or rubber hose indicates a failed regulator. Leaking injectors should be tested using an injector drop test. A contaminated IAT sensor can also contribute to a rich condition.

Anonymous 2018-07-04 12:22

I'll try both the fuel pressure check and the injector leak test. Previously, I replaced the O-rings on cylinder 1's fuel injectors—thought it fixed the issue—but I’ll verify again. I also suspect my intake manifold gasket may be damaged. A prior owner reportedly bent the gasket during installation, making proper alignment difficult. I’ve already checked the IAT sensor and noticed the plastic part wiggles while the bolted section remains solid.

Anonymous 2018-07-04 13:42

O-rings alone won’t cause a rich condition—leaking injectors due to carbon buildup preventing proper closure are more likely. Intake gasket leaks typically cause lean conditions, not rich ones. If the IAT sensor is part of the MAF system and has a wiring harness, it could be faulty. A separate IAT thermistor with skewed readings might mislead the engine control module (ECM). Without a scan tool to compare PIDs against actual engine temperature, diagnosis is limited. Confirm fuel pressure, perform an injector drop test, inspect the fuel pressure regulator for ruptured diaphragm, and check for a faulty O2 sensor or heater circuit. A defective O2 sensor sending false rich signals can trigger this code. Do you have access to a scan tool?

Anonymous 2018-07-05 13:45

Check your MAP sensor reading with the key on but engine off. Compare that value to local barometric pressure—any small deviation will significantly affect fuel trim, especially in a speed-density system like the 2000 Dodge Stratus 2.5L.

Anonymous 2018-07-05 15:10

I haven’t had time to inspect due to extreme heat (currently 101°F), but I’ll check tonight. There’s moisture underneath my intake manifold gasket, which may indicate a leak. Also, I don’t have a MAP sensor—does that affect the diagnosis or is there another way to assess fuel trim behavior?