ECM codes P0174 and P0153

KNIGHTSCHARIOTS

MEMBER
2001 FORD ESCAPE
3.0L
V6
4WD
AUTOMATIC
303,000 MILES

Intermittent DTC P0174 unconfirmed by computer and scan tool. A consistent confirmed DTC P0153 smoke tested the engine since last Question was asked and have found EGR valve leaking smoke at valve body vent holes. With test being performed.I believe it should be closed and not leaking from what I have read.I think its stuck open and intermittent close/open with the lean code P0174 as it goes away then returns at fuel up or sometimes driving haven't had a chance to remove her and check for carbon build up. I also think the o2 sensor is fine after graphing it and snap throttle they all show with in acceptable range. Recent scan tool freeze frame data is as follows. Fuel sys1 clsd ( calc load % 31.8(coolant temperature 176 (engine RPM 1597( vehicle speed 25 mph ( STFT1- 0.8 ( LTFT1 - 5.5 ( STFT2 -16.4 (LTFT2- 24.2. Do you think EGR causing P0174 Intermittent and the P0153? I'm going to change the EGR valve re-smoke test it and see if the P0174 goes away.I don't think the P0153 is a bad O2 sensor.

4 Replies

JIS001

MECHANIC
3,411 POSTS

When doing a smoke test, some smoke will escape out the EGR. If the EGR were stuck open you would get a hard start or a random misfire which in this case you have neither.

P0153 is a fault with the oxygen sensor on bank2 sensor1. Looking at your fuel trims you posted it appears bank2 is running really lean. I would recommend you look for an intake leak around bank2 or exhaust leak as well. If no leak then your upstream oxygen sensor on bank2 is the culprit causing these codes.

But as stated earlier, verify you have no intake or exhaust leaks near the oxygen sensor. Let us know what you find please.

Check out the diagrams (below). Please let us know what happens.

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