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Old 08-05-2022, 06:36 PM   #1
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jimmcdaniels is a jewel in the roughjimmcdaniels is a jewel in the roughjimmcdaniels is a jewel in the roughjimmcdaniels is a jewel in the rough
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Default 98 SC2 P171-Fuel trim System Lean, help fix Please!


My pristine & stock automatic 1998 Saturn 1.9 DOHC SC2, 130K miles now has
Only DTC
P171(Fuel trim System Lean) and it seems to crank a bit more than it should before starting.

When I clear the code with a scanner, I get the code again within a few days of driving.
Before this, I replaced the Front O2 sensor with a Denso w/oem connector because I was getting codes
P171(Fuel trim System Lean).
P131(O2S circuit low voltage sensor 1)
P137(Fuel trim system lean)
P1133(O2S Insufficient switching sensor 1).


I've read that P171 can be caused by any vacuum leak, commonly at the intake manifold gasket-needing replacement.

But I haven't found any obvious hose leak.
With the engine idling, I did spray starter fluid on vacuum hoses and around the intake area. But no change in idle was noticed.

I suppose the next logical thing I need to do is replace the intake manifold gasket and then clear the P171 and see if it comes back.

My scanner did not have a freeze frame accompanying the P171.
But I did take some screen shots of live data at idle, after I came home from driving around, shown below.

I am still new at interpreting scanner data into something investigative.

Any suggestions?

Attached Images
File Type: jpg IMG_2352 2.jpg (48.4 KB, 9 views)
File Type: jpg IMG_2351 2.jpg (27.4 KB, 6 views)
File Type: jpg IMG_2356 3.jpg (48.4 KB, 5 views)
File Type: jpg IMG_2353 2.jpg (49.8 KB, 5 views)
File Type: jpg IMG_2354 2.jpg (45.0 KB, 4 views)
File Type: jpg IMG_2355 2.jpg (49.4 KB, 4 views)
File Type: jpg IMG_2330 2.jpg (39.8 KB, 4 views)
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