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Alot of problems

2K views 12 replies 5 participants last post by  Sam 
#1 ·
Here it is in a "nutshell"
2002 Ford Taurus, flex fuel engine. Cold air intake installed, and SCT Tune !

1. Replaced cam shaft sync.

2. mechanic broke tips where dpfe lines connect to egr back pressure sensor.

3. mechanic said it would not affect car.

4. car started running like crap, THREW DTC CODES 171, 174

5. Replaced EGR Backpressure Sensor.

6. Codes are still coming up. NOTE: car is tuned with an SCT Tuner, i am running the 87 octane tune.

7. The only modifications to the car are the SCT Tune, and a cold air intake.

8. I returned the car back to stock tune ( that made it throw same codes 171, 174

9. I then returned the car back to the 87 octane tune.

10. Same codes again, but not as many.

Any suggestions ? Maybe a vacum leak, bad o'2 sensors, bad mass air sensor ?

** Will SCT's 90mm mass air sensor help in this matter, and give me a solution/better performance ?

* Don't know if this helps but the mechanic had to remove the upper intake plenum in order to install the camshaft sync. because the wire harness next to camshaft sync. was in the way to install the new one. When he removed it there was no gasket between plenum and intake. *

Should i remove the plenum again and apply some RTV sealant between the mounting surface ?

I dunno, i am at my wits end with this problem.

Thanks for any input !

P.S. Could i send the tuner back to SCT and have them adjust the " Lean Fuel Burn ?? :unsure:
 
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#2 ·
2. mechanic broke tips where dpfe lines connect to egr back pressure sensor.

3. mechanic said it would not affect car.
Wrong! When the EGR valve opens it will be sucking in regular air instead of exhaust gases. Regular air has high oxygen content, so this will act exactly like a vacuum leak and cause lean codes when the EGR valve is open (normally during cruise). Replace the DPFE, put the hoses back on, and I think your P0171/P0174 codes will go away.

The intake manifold does not need to be removed to change the cam syncro (but the throttle body probably does). Yes the wiring harness is in the way, but you can usually loosen it enough to get it mostly out of the way.

The intake manifold should have gaskets. But they are usually held in the bottom of the plastic manifold, so I'm guessing you just didn't see them if you were watching. Do not use RTV.
 
#3 ·
Your mechanic is an idiot. Absolutely no need to remove the UIM to replace CKP/syncro assembly.

Of course the DPFE will not function with the nipples that is uses to measure pressure are broken off. Non functional DPFE will cause lots of problems. What an idiot mechanic........

I would not trust what this guy says about the gasket being missing. He already lied to you twice. With no gasket, you will have vacuum leaks 100% guaranteed, generating 171/174 and causing rough running, etc. Just buy a new UIM to LIM gasket and install it. They are cheap.
 
#5 ·
eeeeeeeerrrrrrrrrrrrrrtttttttttttttttt brakes

one more thing, ever since this started happening my brakes have a different feel now. have to really stomp on them to get it to stop, but it does not react like that all the time.

Whats up with that ? Thanks
 
#7 ·
one more thing, ever since this started happening my brakes have a different feel now. have to really stomp on them to get it to stop, but it does not react like that all the time.

Whats up with that ? Thanks

Power brakes are "vacuum assist"; you have a vacuum leak, therefore little or no assist.

There's a check valve in the system, so when the system can create enough vacuum for the brakes, the check valve holds that vacuum in a reserve. Once you deplete that reserve (when you step on the brakes), the system has a hard time rebuilding the reserve due to the leak.
 
#6 ·
I want to ask, when you replaced the EGR pressure sensor did the engine stop running badly? Could have already fixed those two codes and they just have not cleared yet.
 
#9 ·
If you still have P0171/P0174 codes and you're sure the hoses are on the DPFE and EGR tube correctly, then you probably have some other vacuum leak. If you still think you don't have intake manifold gaskets, you should probably take off the upper intake manifold again and inspect the gaskets. They look like the number 8. One trick for finding vacuum leaks is to squirt a bottle of water around the intake manifold and vacuum tubes and listed for the sound of water being sucked in if you have a leak.
 
#10 ·
^
Or do the cigar smoke test. I promise I'm not a smoker lol, but I think this test works pretty well, especially for larger leaks. Just blow cigar smoke into a vacuum tube with the motor off. If you don't have a gasket, you'll see it come out all over the UIM.
 
#12 ·
cracked vacum line, the one that runs along the firewall. fixed for now, i expect some new " problem " before to long. QUESTION: Do i have to return my car to stock ecu settings, or i can i just leave it tuned with the SCT ??
The smallest little things can make your life hell, like the cracked line.......lmao Thanks All, Mike
 
#13 ·
You can leave it tuned... It will be better for the car to go back to stock, but keeping it tuned shouldn't cause vacuum lines to crack and crumble. Congrats on your fix.
 
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