1996 4.6L Running Too Lean
Thunderbird281
06-19-2009, 05:34 PM
I have a 1996 Ford Thunderbird 4.6L with 154,000 miles on it. I recently had the MAF Sensor go on me so I replaced it. However, after I replaced it I started getting spark knock and I got a DTC Code saying "System Too Lean". I checked for vacuum leaks and replaced vacuum hoses that looked like they could be leaking. The idle is still smooth and I don't hear any vacuum leaks so I'm pretty sure that's not the problem. I changed the Idle Air Control Valve but that didn't solve the problem. The oxygen sensors only have about 40,000 miles on them so I don't think it's that either. Does anybody have any advice as to what could be causing it to run lean? Thanks in advance.
97Bird
06-21-2009, 02:32 PM
Is the code telling you only one side is running lean or both? Is the ERG valve stuck open? The O2 sensors could still be the problem.
Thunderbird281
06-22-2009, 05:12 PM
How do I tell if it's stuck open?
97Bird
06-22-2009, 06:20 PM
You will have to remove it to check and clean it. Use a vaccuum pump to see if it opens and closes.
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