Contour Enthusiasts Group Archives Forums General Troubleshooting CEL mystery

ok here is the deal with the car, cel comes on get the codes read they are p0171 and p0172, WTF i searched and found something about a zetec having these codes like the duratec but found no answers about a duratec, the o2's are only about a month and a half old so i don't think it is those, also it only threw these codes when i was running 19lbers, since then i have switched back to my stock 17lbers and the CEL has since returned (dont know what codes yet need to get them read) assuming the codes are the same what areas should i look at for trouble?? most of my mods are listed below so if any of those would affect it let me know

just a side note on my PCV oil seperator the lines get sucked almost flat with the car running (stupid cheap fuel hose) would that be the problem, also plan on fixing it soon anyway so if it is thats even better

need to figure this out soon got to get inspected before the end of Oct

As you pointed out PCV oil seperator the lines get sucked almost flat with the car running,
That this could be a problem!

Diagnostic Trouble Codes (DTCs) P0171 bank (1) (cylinder #1) and DTC P0174 bank (2) indicate the fuel/air ratio is too lean. The fuel adaptive system is at the rich correction limit.

DTC P0172 bank (1) and DTC P0175 bank (2) indicate the fuel/air ratio is too rich. The fuel adaptive syste is at the lean correction limit.

DTCs HO2S Reference list:

-- HO2S-11 = DTCs P0171 and P0172

-- HO2S-21 = DTCs P0174 and P0175

Possible causes:

Fuel system

-- Excessive fuel pressure.

-- Leaking fuel injector(s).

-- Leaking fuel pressure regulator.

-- Low fuel pressure.

-- Contaminated injector(s)

Induction system

-- Air leaks after the MAF.

-- Vacuum leaks.

-- Restricted air inlet.

-- PCV system.

-- Fuel purge system.

-- Improperly seated dip stick.

EGR

-- leaking gasket.

-- Stuck open EGR valve.

-- Leaking diaphragm.

Base engine

-- Oil overfill.

-- Cam timing.

-- Cylinder compression.

-- Exhaust leaks before or near the HO2S's.

-- Check air intake for leaks, obstructions and damage.

-- Check air filter, air filter housing for blockage.

-- Verify integrity of the PCV system.

-- Check for vacuum leaks.

When you say 'SVT MAF' I'm assuming you are referring to the black plastic body MAF? Put your old aluminum MAF back on. There is no SVT-specific factory MAF. There is, however, a specific MAF for all 2K Contours, because it was Mechanical Returnless Fuel, which did have different injector specs and MAF calibration curve compared to the standard return system used in all other Contours. But for any given model year, the same MAF was used in both SVT and non-SVT V6s. I tried this myself when I put the conical filter in my '99 Mystique, along with the attached plastic MAF, and it threw a P0171 in 5 minutes.

Did you also reflash your PCM with the SVT calibration when you went to the 19# injectors? If not, you wouldn't get a P0171/2 lean code set, but you probably aren't taking full advantage of the upgraded injectors.

the maf isnt on there forgot to say that

Clean the MAF first with Carb Cleaner.

ok so i will clean the MAF and keep you all posted, will also get the codes read to see what the new ones are

I believe according to the post I made, from my service manual, it's your PCV hoses.

You stated they become flat and the post I gave you, stated that the code could from the PCV system.
I wouldn't waste to much time on the MAF.

ok here is an update on this problem, i replaced the hoses with some from advance, reset the ecu, drove it a little yesterday CEL came back on, was too late to get it read so i got it read today, the codes were p0171 and p0174, reset the ecu again after i epoxied my oil seperator to make sure it was not leaking any, and went to driving again, after a little bit the CEL has come back on, dont know the codes yet but here is an update on some changes to the car

running the stock injectors, stock maf, replaced the upper o2 sensors about 2 months ago

also on a side note, when i was putting the stock injectors back in i noticed that some of the brown plastic things on the end of the injectors were cracked but not broken off, would that have any effect on the A/F i believe the injectors are still working, but am not sure

gonna check my fuel pressure regulator to see if that needs to be replaced as it is orignal, i dont know about the condition of the UIM gaskets as i have had to pull it off a few times since i replaced the originals, so those might be leaking, but i got no clues gonna see what others did when they fixed theres

also forogt to add my throttle body has a crack in it, will post some pics when it is daylight and i can get some, and i have not tried cleaning the MAF yet but will try this tommorow also

keep you updated

When you replaced the hoses did you check the plastic one that goes from the
PCV to the EVAP emissions valve on the firewall.
This can develop small pin sized holes in it and be hard to detect.
Happend to me and lots of others.