code 41 lean
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Joined: Jul 2002
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code 41 lean
First off, Thanks for all the help so far in my previous posts
My 1986, 302 EFI Bronco is putting out a code 41, and there is some loud "lean backfires?" sometimes just after WOT at highway speed. Fortunately the cooling system is able to deal with the extra heat created, although tranny oil gets hotter than I would like since hot exhaust parts warm its pan
My timing has finally been set properlly by an experienced mechanic, vacumm leaks have all been fixed "im fairly sure".
O2 sensor is new, exhaust leakage fixed, and fuel system has correct pressures at WOT & idle "havent checked loaded pressure though"
Could EGR system be semi malfunctioning, causing lean code without setting an EGR code?
Could my injectors be clogging, and if so are the injector flushes advertised at garages of any benefit?
**MOST IMPORTANTLY** I have several thousand miles I must drive this month, can I drive lean without doing any major damage?
My 1986, 302 EFI Bronco is putting out a code 41, and there is some loud "lean backfires?" sometimes just after WOT at highway speed. Fortunately the cooling system is able to deal with the extra heat created, although tranny oil gets hotter than I would like since hot exhaust parts warm its pan
My timing has finally been set properlly by an experienced mechanic, vacumm leaks have all been fixed "im fairly sure".
O2 sensor is new, exhaust leakage fixed, and fuel system has correct pressures at WOT & idle "havent checked loaded pressure though"
Could EGR system be semi malfunctioning, causing lean code without setting an EGR code?
Could my injectors be clogging, and if so are the injector flushes advertised at garages of any benefit?
**MOST IMPORTANTLY** I have several thousand miles I must drive this month, can I drive lean without doing any major damage?
Post Fiend
Joined: Nov 2002
Posts: 9,987
Likes: 7
From: Memphis, TN
The TAB & TAD aren't connected to the smog pump plumbing (thermactor check valve) - only indirectly. I'd check the ignition timing, TPS, MAP, PCV hose, & oxygen sensor. On the old oxygen sensors like that (one wire, right?), there's a service interval - have you changed it lately? The engine may be running normally, but REPORTING a nonexistent lean condition. You'll have to diagnose it to find out if it's real or not, but an emissions testing station should be able to tell you in an instant with a sniffer.
Driving with a significantly lean condition for a long time can make the engine run hot, burn valves, crack connecting rods, and even burn holes thru the pistons.
Driving with a significantly lean condition for a long time can make the engine run hot, burn valves, crack connecting rods, and even burn holes thru the pistons.
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