Check Engine Light, High Manifold pressure says Jiffy Lube

I have had my check engine light on for a couple months now and I went to Jiffy lube the other day for an oil change and to tell me what it the light was on for. They said I had high manifold pressure but couldn’t tell which manifold it was. Is there any danger to either my car or my family if I leave this alone for a while longer, and how much would it take to repair this at any given mechanic?

1999 Oldsmobile Eighty-Eight LS 173000miles

Did Jiffy Lube give you a printout of the codes(s)?

Without them, it’s anyone’s guess


First, take it to a real shop and never go back to Jiffy Lube again. JL does not have the expertise, equipment, or experience to be doing this level of work.

What I suspect they were telling you is that the ECU had stored a fault code for a high Manifold Absolute Pressure (MAP) sensor reading. The MAP sensor is one of the sensors that tells the ECU the “engine demand”, or what the engine requires for fuel under specific engine operating and load conditions. It’s one of a myriad of “engine demand” inputs for the ECU that it uses to meter the fuel.

The cause is probably as simple as a bad sensor. A good shop can determine this and change the sensor for you if that’s what it turns out to be.

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Jiffy lube is not a place to get your car diagnosed. As is obvious from their reply to your question. Codes ar in the form of Pxxxx with each X marking a digit. They don’t tell you what part is bad, just which system to troubleshoot.

To answer the question of “safe to drive” … yes, to a point.

The engine is not running optimally. You are likely getting worse fuel mileage, and continuing to drive like this might damage your catalytic convertor.

Seek help not from Jiffy Lube but a good independent repair shop.

To be honest I wouldn’t trust “iffy-rube” to correctly diagnose a flat tire. Just this persons opinion.


And many, many others.

I remember returning a rental car with a leak in a tire. I told the attendant about it but he didn’t even know how to use a tire gauge and had to ask a supervisor. That’s Jiffy Lube. Use at your own peril.

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You returned a rental car to Jiffy Lube, Bing?

Expecting someone at Jiffy Lube to be able to diagnose and/or fix an automotive problem is tantamount to believing that a cashier at CVS or Walgreens is capable of diagnosing or (God forbid!) treating someone’s medical problems.

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If your engine seems to be idling too high listen and look under the hood for a vacuum leak. You can often hear it.

Go to a car parts store like Autozone, etc. They’ll read your codes and give you a printout. Let us know what codes are on it (like P0042, that kind of thing). Once we know the exact codes we can help a lot more.

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Yes, if the check engine light is lit, there’s at least one diagnostic code stored in the computer memory. Each one will start with a “P” followed by 4 digits. Like P0335. If you post the codes, you’ll get some more help here. An oil change chain stores isn’t likely to have the expertise to offer you any useful guidance on this. But if your auto parts store will print out the OBD II codes for you, that info would be helpful.

JL wants to move into other car repairs according to radio ads around here.

Their employees are even less-qualified than the guys at AAMCO–who now claim to be able to repair any automotive problem.

What a load of… :poop:… awaits an unsuspecting American public…

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Shell Oil wants to get every last penny out of you they can.

It could be any of a number of things. The exact error code would help narrow it down.

Check your oil and stay away from Jiffy Lube.

As one of our members (Joseph Meehan) used to say,
Don’t go to Jiffy Lube. Not even for directions!


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Question: How do you find your neighborhood Jiffy Lube?
Answer: Follow the trail of oil from the cars they left the drain plugs out of after an oil change