1997 Ford E-150 OBD Fail Lean EVAP EGR

Avatar
DWESTMAN
  • MEMBER
  • 1 POST
1997 E150 Ford Van
98,880 miles
Failed OBD test

Codes:
0455 EVAP Control System Leak detected (gross leak)

P0401 EGR flow insufficient detected

P0171 - System too lean (Bank 1)

P0174 - System too lean ( Bank 2)

Can I fix this myself? I paid $650.00 two years ago for similar error codes - never really fixed problem since repair engine light was still on - now burned out but failed test.
Dec 29, 2006 at 8:23 AM
Advertisement
Avatar
SERVICE WRITER
  • ✓Experienced Mechanic
  • 9,123 POSTS
On the EVAP leak, I would first check to make sure the fuel cap is on tight. If any corrosion exists on the lip of the neck, clean it off and apply some vaseline around it. It doubt, get a new cap. A cap would cause a large leak in the evaporative system, but a rotte fuel filler neck could do the same. If the above doesn't work, find a good independent shop that can smoke the system.

On the Egr flow, I would pull the egr valve and clean it, and check the passageways for obstructions. Use a good carbon removal cleaner. Castle make cleansrite.

This may be contributing to the lean codes, but I am starting to venture into BS :lol:
Dec 29, 2006 at 2:24 PM
Avatar
INDYUKE
  • ✓Experienced Mechanic
  • 416 POSTS
On the EGR fault I would not only pull it and clean it, but would also check vacuum and electrical lines leading to it for any problems or breaks. You could have a rotted diaphragm in the EGR valve itself causing it to not open or not open very far, or you could have a bad EGR position sensor sending wrong readings.

Since both banks are running lean, I would think weak fuel pressure that's affecting the entire system rather than a plugged injector somewhere which would likely only affect one bank. Unless you had plugged or partially plugged injectors on both cyl banks. I would check to make sure your air filter is clean and free of abstructions, fuel system presssure checks out ok, fuel system is squeaky clean, there are no vacuum leaks anywhere, both intake air temp sensor and mass airflow sensors are working correctly (though we don't suspect those because a code would be set for them as well if they weren't working well) and check to make sure there aren't any vacuum leaks anywhere. Those are things you can easily do yourself, and those are the things that most directly affect fuel delivery. Good luck.
Jan 1, 2007 at 4:52 AM

Suggested Repair

Tighten or replace the fuel cap, clean any filler-neck corrosion, and smoke-test the EVAP system if the gross leak remains. Remove and clean the EGR valve and passages, and inspect its vacuum lines, wiring, diaphragm, and position sensor. For lean codes on both banks, check the air filter, fuel pressure, fuel-system condition, and vacuum leaks, and verify the intake air temperature and mass airflow sensors.

Conversation Summary

A 1997 Ford E-150 van with about 98,880 miles failed an OBD test with P0455 EVAP gross leak, P0401 insufficient EGR flow, and P0171/P0174 lean codes on both banks. A prior repair had not resolved the check-engine light. Experts advised checking or replacing the fuel cap and inspecting the filler neck, then smoke-testing the EVAP system if needed. They also recommended cleaning the EGR valve and passages and checking its vacuum, electrical, diaphragm, and sensor operation. Because both banks are lean, they suggested checking fuel pressure, the air filter, vacuum leaks, and related sensors rather than assuming a single plugged injector.

Add a reply
Join 2CarPros for free, one of the most advanced car repair communities on the internet. From first-time drivers to seasoned mechanics, everyone is welcome to reply, share details, and get better answers. You can add a temporary image or video first; uploads are limited to 20 MB.

Frequently Asked Problems for This Vehicle