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engine light still on

I

i will end you

CEG'er
Joined
Nov 9, 2006
Messages
60
well i replaced a laundry list of parts, and im down to 3 codes. po420 and if i remember correctly po171 and 0174. i may not be correct on those last two but they lean bank one and lean bank two. the scanner also said that the 0420 was insufficient catalyst. anyway the jerk at tuffy service center who promised me that the 475 dollars i spent there would get rid of the light, it didnt. well the light stayed out for 45 minutes which im asumming was a good old ford drive cycle. then it comes back on. I took it back after i replaced all th o2 sensors, which he wanted to do but i wouldnt give him the extra 500 he wanted for it. so after i took it back it came up with those numbers and he told me i needed new cats which i assumed that he ment precats. can anyone confirm this before i punch mine out and wire up the mils. i plan to take the manis off to do it but i dont want to go through all that if i dont have to. thanks-chaz
 
thanks beans. i have already done the upper and lower, new dpfe, new egr, new coil pack, new plugs/wires, cleaned the tb, cleaned the maf, and finally changed all the o2's. sorry i should have listed all that was done recently. hope this helps a lil
 
Elyria,

The P0171 and P0174 "is" most probably causing the P0420. P0171 and P0174 "is" a massive vacuum leak. I would look for a broken hose or hole in the exhaust first before looking elsewhere.

Edit. Read this thread for good info.
http://www.contour.org/ceg-vb/showthread.php?t=4598&highlight=p0171

From TSB,

P0171 - System Too Lean (Bank 1)The Adaptive Fuel Strategy continuously monitors fuel delivery hardware. The code is set when the adaptive fuel tables reach a rich calibrated limit.

Fuel System:
· Contaminated fuel injectors
· Low fuel pressure or running out of fuel (fuel pump, filter, fuel supply line restrictions)
· Vapor recovery system (VMV)
Induction System:
· MAF contamination
· Air leaks between the MAF and throttle body
· Vacuum leaks
· PCV system concern
· Improperly seated engine oil dipstick
EGR System:
· Leaking gasket
· Stuck EGR valve
· Leaking diaphragm or EVR
Base Engine:
· Exhaust leaks before or near the HO2S
· Secondary air concern
Powertrain Control System:
· PCM concern

P0174 - System Too Lean (Bank 2)

Same diagnosis as DTC P0171, but Bank 2.

See Possible Causes for DTC P0171
 
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sorry for the delay in this reply. tony, someone told me that if i indeed had cloged cats that my car would run so horribly that i would have trouble getting past 40 mph. he told me that on his 3 litre taurus, when his clogged the car was barly drivable. is there any truth to that? i did read the info on the link you provided. have you ever seen this happen before? i am having trouble beleaving that a vacumme leak could cause all the problems im experiencing.(sp) i have never really had a ford v6 in the past. i have always had hondas and nissans that use map's. the maf is all new to me. im going to try the carb/choke cleaner method this weekend as described in the link you posted. ill try to have an update as to my findings as soon as i can.thanks for all your help.
 
" someone told me that if i indeed had cloged cats that my car would run so horribly that i would have trouble getting past 40 mph. he told me that on his 3 litre taurus, when his clogged the car was barly drivable. is there any truth to that? .................. have you ever seen this happen before?"

Yes and yes.

" i am having trouble beleaving that a vacumme leak could cause all the problems im experiencing."

It's your car. You may believe anything you want. :shrug: ;)
 
sorry for yet another delay in posting, ive been really busy. anyway tonite i went through a whole can of carb cleaner just like the article said trying to find a spot where vacume leak would cause an idle surge. the only place spraying it made the engine change idle was when i sprayed it directly at the air filter. so is it my cats? or do i possibly have a messed up ecu, or something else? the only thing i havent tryed is punching out the cats and wireing in the mils. im at a total loss. if i cant get this light to go out i think im going to sell the car. ive just never had this big of a problem fixing a cel. please help im open to all suggestions. thanks-chaz
 
Many times, the vacuum leak is small enough that hitting it with carb cleaner WILL NOT cause a change in idle conditions (the computer compensates too fast) but can still cause a P0171 & P0174 compb.

I've had to resort to using my scanner in live mode and watching the short-term trims in order to see the effect of the spray.

Steve
 
spraying it in your filter did what it is supposed to do.. cause the car to sumble, etc. What you are doing when looking for leaks is trying to find OTHER ways in the intake BESIDES the filter.

spraying the filter was defeating the purpose.. :)
 
spraying the filter was defeating the purpose.. :)[/quote]





i understand that spraying the filter defeats the purpose. I was merely stating that it was the only place that when sprayed made any amount of difference. i started by spraying it so i would have a better idea of what to listen for provided i hit a spot with a leak. In the end I couldn't find another place that made it stumble or rev up or anything. I don't have a scanner capable of reading the way that was mentioned a few posts up. anyone close to the cleveland area that could possibly help me out with this?
 
I had that code combo before and the culprit turned out being the wires on the maf sensor pull out the wires and clean them and put them back in and reset your pc. The wire on my maf were a little toasty :laugh:
 
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