P1151

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Jul 26, 2005 | 10:11 PM

nightme_02

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From: Spring Hill, KS

P1151

Using Autozone to pull the codes I have found that P1151(lack of switching), P0301 (misfire Cyl 1), P0304 (misfire Cyl 4) were all setting off the CEL. I have seen Rockledge's responses posted concerning the P1151 code, and I am curious if this code (P1151) coupled with these other two codes point to a more specific part or piece that is potentially malfunctioning?

--Thanks

Jul 27, 2005 | 03:18 PM

nightme_02

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From: Spring Hill, KS

* bump *

Jul 27, 2005 | 08:37 PM

Ken00

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From: South Jersey

If the O2 isn't switching you could be running lean or rich, causing a misfire. What year/engine, you sig says 1994 which wouldn't have ODB-II codes.

Jul 27, 2005 | 08:50 PM

nightme_02

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From: Spring Hill, KS

Sorry Ken, it's actually a '96 Windstar with a 3.8L . Since there isn't a forum area (that I could find) for Windstar's, and I have found very good results here I went ahead and posted here!

But if the O2 isn't switching that could mean that it's not exactly the O2 sensor, but a possible vaccum leak or something other than the O2 acting up?!

Thanks again

Jul 27, 2005 | 10:09 PM

79_custom

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From: Pikeville, KY

P1151 Lack of HO2S-21 Switch, Sensor Indicates Lean Condition.

Any Code Following P0300-P0306
Fouled, cracked or incorrectly gapped spark plugs
Low compression
Vacuum leak
Faulty injector
Powertrain Control Module (PCM) calibration
Plugged EGR orifice(s) in each primary port of the lower intake manifold

Hope this helps

BTW If it is the EGR Ports clogged in the runners in the IMRC you will need to get new bushings, they will break upon removal.

Last edited by 79_custom; Jul 27, 2005 at 10:14 PM.

Jul 28, 2005 | 07:18 AM

nightme_02

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From: Spring Hill, KS

It actually helps a lot 79, thanks for the information. Will definately help in my search to keep the dang CEL off!

Thanks again

Jul 28, 2005 | 08:17 PM

Ken00

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From: South Jersey

I'm leaning towards a vacuum leak but I'm not fammilar with that engine's issues.

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Jul 28, 2005 | 10:35 PM

79_custom

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From: Pikeville, KY

One way For Sure you will know its the EGR ports in the IMRC is to unplug the EGR only if there is a rough Idle. If the idel goes back to normal its your EGR Ports clogged in the runners in the IMRC. Check that first then come back... Id almost bet your idle will go back to normal.

What helps the H02S switch is the STFT (Short Term Fuel Trim). The STFT goes between - and + of 0% and when the H02S sees a misfire it really sees More or less 02 in the exhaust. If there is a misfire say like a injector fails the H02S will see a Lean mixture because of the unused Oxygen in the exhaust and then the STFT pick that up from the H02s and the the STFT goes + off 0% and stays Positive till the LTFT gets back to normal (Long Term Fuel Trim)and till the PCM sees that the H02 Starts to switch again. That is what throws a Misfire code if the LTFT cant stablize.

Last edited by 79_custom; Jul 28, 2005 at 10:55 PM.