p1131 p1151 codes only. Idles fine! | Ford Explorer Forums - Serious Explorations

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p1131 p1151 codes only. Idles fine!


February 4, 2015
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City, State
Canary Islands
Year, Model & Trim Level
97 SOHC Explorer II, 2WD
Hi from Spain.
My 97 Explorer SOHC got those two codes but engines idles fine! I guess I got a leak somewhere but can’t find it. Both banks running lean. No other codes stored.
Recognized that the egr valve makes noise when rpm increases but holds vacuum perfect! It is defect?

On the green line to the egr valve is vacuum but not as much on other hoses! Normal?
All lines are checked. Under water tested ;)
Solenoid new.

DPFE and egr solenoid new and oem.
Egr tube checked. No leaks.

Checked all hoses. Sprayed everything.
O2 sensors are new! Tested all wires to pcm.

Maybe the pcv hose that goes to the breather between the manifold? pcv new.

Exhaust leak?
Intake manifold gaskets?

Engine runs fine but I did not pass emissions test.

I’m going insane....