In case you missed this, after warmup the ECM goes into closed loop mode and uses several sensors to adjust engine fuel delivery and timing. A quick check with a good code reader in live data mode should tell you which sensor(s) is acting up.
When it warms up to operating temperature the O2 s may be causing problems . As they age they respond too slowly or stick on too rich or too lean causing flat spot response .
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In case you missed this, after warmup the ECM goes into closed loop mode and uses several sensors to adjust engine fuel delivery and timing. A quick check with a good code reader in live data mode should tell you which sensor(s) is acting up.
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If a faulty egr valve is stuck open or partly open it has a similar effect to an intake air leak which can cause those problems...
When it warms up to operating temperature the O2 s may be causing problems . As they age they respond too slowly or stick on too rich or too lean causing flat spot response .