2000 Chevy S-10 Lean Misfire

1930 ALL OTHER MAKES ALL OTHER MODELS
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82-454
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I keep getting a 171-174 code, This is a lean condition both banks. I also get a 300 code. This is random miss-fire. It bucks at part throttle when its cold until the temp gauge reads 195 when the themostat opens. This is in a 2000 S-10 4.3 V6 with 190,000 miles. Do the fuel injectors need to be cleaned? Has anybody had this same problem. Thanks, Roger
Dec 7, 2006 at 12:26 PM
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GARFIELD
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Since from your email that you have already had a tune up lets look at some of the other items that would give you the same problems. Since you are getting codes 300, 171, 174 all at the same time. I would put a vacuum gage on the engine to see if you have a vaccum leak. Check your EGR valve if it is staying open at idle it will give you a large vaccuum leak. If the vacuum is good.
Dec 8, 2006 at 10:25 PM
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82-454
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I have an autometer vacuume gauge installed and it shows no problems. I have changed the fuel filter but not this year. It could use a set of plugs. I'm going to check the EGR next. Thanks, Roger
Dec 11, 2006 at 7:46 AM
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Suggested Repair

With the vacuum gauge already reading normal, inspect the EGR valve for sticking open at idle, which can cause lean codes on both banks and a random misfire. Replace spark plugs if they are due.

Conversation Summary

The owner of a 2000 S-10 4.3 reports codes 300, 171, and 174, with part-throttle bucking when cold until the thermostat opens. The expert suggested checking for a vacuum leak and an EGR valve stuck open. The owner says the vacuum gauge is normal, the fuel filter was replaced earlier, plugs may be due, and plans to check the EGR next.

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