Service engine light, EGR valve flow and bak 1 O2 sensor error

BARB123

MEMBER
2000 PONTIAC BONNEVILLE
6 CYL
AUTOMATIC
185,000 MILES

2000 Pontiac bonneville SSEI with 185000 miles. About 3 weeks ago I started getting an intermittent service engine lgt. Scanned at auto parts store. I was told I might need to clean the egr valve. The egr valve was replaced a week ago and after about 15 miles of driving the light came back on again and stayed on. Before the egr valve was replaced I had noticed a drop in my gas mileage a couple of weeks before the service engine lgt had started coming on. After the egr valve was replaced, I got another scan done, now I have 2 codes (p0401, p1133) low egr flow and bank 1 o2 error. Gas mileage is still bad. One year since spark plugs and fuel filter replaced. What do I check next? What could be the problem?

3 Replies

MERLIN2021

MECHANIC
17,250 POSTS

401 is innadequate egr flow, was the port cleaned out while the egr was off? If yes, the position sensor needs to be replaced, if not clean port right thru.

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Tuesday, March 15th, 2011 AT 8:17 PM

MERLIN2021

MECHANIC
17,250 POSTS

P1133 is either the bank 1 sensor 1 o2 sensor sluggish, or the A/C pressure sensor high voltage, you need a scantool to watch the o2 voltage switching. It should keep switching from high to low continuosly graph will have many waves.