Check engine light comes on and code shows EGR valve – code 71 – We have replaced the egr valve and the egr heat sensor. disconnect battery , start it, will drive ok until we stop to get gas then start it again and in about 5 or 6 miles, check engine light comes on and we get the same code. we disconnect the battery and the check engine light goes off. drive it until gas is needed again , stop, put gas in, drive it about 5 or 6 miles again and the check engine light comes on. disconnect battery again and light goes off. any thoughts
Vacuum canister is the first thing that comes to mind. I would be curious if you only filled the tank half way and tested it. However lets look at the code information.
Toyota Engine Code 71 – EGR System Malfunction
Diagnosis
With the engnie coolant temp. at 140F or more, 240 seconds from start of EGR operation. The EGR gas temp. is less than 131F and the EGR gas temp. has risen less than 68F during the 240 seconds. (2 trip detection logic)
Possible Causes
- Open in EGR gas temp. sensor circuit.
- Open in VSV circuit for EGR
- EGR vacuum hose disconnected, valve stuck
- Clogged in EGR gas passage
- ECM
You may want to look for possible vacuum hose leaks or cracks. Also look at the wiring connections and the wiring itself for continuity during a wiggle test.