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Matt
Matt, Mechanical Engineer
Category: Car
Satisfied Customers: 21629
Experience:  BEng hons Mech engineering, in auto industry 22 years
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Zafira 1.6, fault code p0171 lean bank 1, had inlet channels

Resolved Question:

Zafira b 1.6, fault code p0171 lean bank 1, had inlet channels cleaned, new egr and still the same, lurching when pulling away and if your traveling at 40-50mph let off throttle when you press it again it lurches. Tickover is a bit low, sounds like it's hunting very slightly
Submitted: 1 year ago.
Category: Car
Customer: replied 1 year ago.
Since my mechanic cleaned the inlet channels the tickover is lower, it was ok before just lurching when pulling away from traffic lights and whilst letting off throttle and back on. He is highly experienced but not familiar with these engines
Customer: replied 1 year ago.
It also turns over quite a bit to start when warm sometimes
Customer: replied 1 year ago.
The engine light would come on and go off sometimes, if it was turned off using a computer it would stay off for about 50 miles but then comeback P0171
Expert:  Matt replied 1 year ago.
Hello 1st check for exhaust leaks before the O2 sensor as if this has been experiencing an exhaust leak then it will have been running very rich as the sensor will see the extra air pulled in as fresh / lean fuelling and be adding fuel to compensate. this can lead to catalyst failure as the extra fuel can re-light inside and melt the catalyst The best way to find an exhaust leak is to run the engine from cold and feel around the exhaust joints with your bare hands - you'll have about 30 seconds before it all gets too hot and you should feel any escaping gas blowing over your fingers
Customer: replied 1 year ago.
Where are they located apparently their is 2 on this car
Expert:  Matt replied 1 year ago.
hello the O2 sensors are both in the exhaustlook on the exhaust manifold for the large bulge of the catylst and there should be 1 sensor just in front and another in the middle of the cat brick
Customer: replied 1 year ago.
Update**** I couldn't find any leaks on exhaust. Today I loosened the egr valve, cut up a can and slid it between to block egr. It now runs and drives perfect, but when the engine is cold the choke no longer works and you have to rev it until it warms a little otherwise it cuts out, when egr isn't blocked off the choke works.
Expert:  Matt replied 1 year ago.
Hello OK if blocking off the EGR helps, then its likely to be breathing through the EGR when it shouldn'tso I'd check over the state of the wiring to the EGR valve as the next step
Customer: replied 1 year ago.
Ok
Expert:  Matt replied 1 year ago.
If this is OK then the continuity between the EGR valve and the ECU socket need to be tested as its likely there's a wire damaged
Expert:  Matt replied 1 year ago.
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