2003 SES OHC "U" total loss of power

[SES Dad]

Time to ask the experts.
I have a 2003 SES OHC "U" with 200k miles that my daughter drives. It recently began to 'miss' during acceleration. No noticable issues at idle. Progressively got worse to the point of no power. Tried to drive it home from her school and didn't get very far before the DPFE hoses blew off. After that happened, it had a bit more power, but still 20 mph max. Gave up and towed it the rest of the way home.
After doing some basic 'garage work' investigation (vacuum leaks, MAF cleaning, etc.) decided it was bad cats due to no exahaust at the muffler.
The only code that had showed to this point was P0171 (Lean bank 1)

Just had the entire exhaust replaced; 3 new cats, pipe, and muffler $900
The exhaust guy told me that they all fell apart and the rear pipe was totally clogged. He also told me that there was a miss somewhere that he noticed during his test drive.

I got it home this week and attemped to address the miss.
I just changed plugs and wires, and a replaced the DPFE (melted)....took it for a test drive.
1 mile down the road, the DPFE hose blew off and I limped home at 10-15 mph. Exact same issue from the beginning.
No codes were set during this 20 minute drive.

I'm not a certified mechanic by any means, but I thought I knew a little something. This one has me baffled. I cannot locate any person with exactly the same issues in the forum; hence new thread.

Any help would be greatly appreciated. At this point, I feel like I've thrown $1500 at it for no good reason.
Hopefully I've include all necessary info; I will clarify anything else if needed. Thanks in advance.

[Breeves002]

Firstly it's an OHV (over head valve), not over head cam. It's a pushrod motor.

Anyways, do you have good exhaust flow now that the cats were replaced?

If those DPFE hoses blew off you should at least have EGR codes. Did you check for pending codes?

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[SES Dad]

Sam,
Sorry for the confusion on my part. I also have owned several Saturns, they are OHC engines....
It appears to have full exhaust flow at the tailpipe.
I do not know about any pending codes as I had to return my borrowed reader.
I should be able to get it back next week; don't want to drive to my local AZ or AA to have them check as I am afraid of other issues.
Rich

[Breeves002]

No big deal! Just wanted to let you know! The other motor that was available in the Taurus was dual overhead cam. The vin U motor was the OHV like you have. I'm happy you knew the vin code.

Anyways see if you have any pending codes. I'm not sure why the hoses would blow off the DPFE if the cats weren't clogged. Anyone else chime in if you have ideas!


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[SES Dad]

Sam,
Will check the codes as soon as I can get my hand on the reader.
Meanwhile, I've been trying to confirm function of the EGR circuit.
At idle, should the EGR solenoid and subsequent EGR be 'engaged' so that the pipe would show no pressure as the gas is passing through? Even at idle, I'm getting significant exhaust pressure at the pipe nipples.
Rich

[behlinla]

Originally Posted by SES Dad

Even at idle, I'm getting significant exhaust pressure at the pipe nipples.
Rich

Something is still clogged. At idle the EGR valve should be closed, so the one nipple shouldn't have any flow. The other nipple that is connected to the exhaust side of the orifice should only have a tiny amount of pressure associated with it. If you lightly rest your finger over the end it should not leak past. If exhaust is leaking past your finger while you rev the engine then you still have an exhaust restriction somewhere.

Normally I would say to check the mufflers because fragments can blow back that far and clog them, but you said they replaced all three cats AND the muffler? If you look under the car do all those components look new?

If you still had a really bad misfire (CEL flashing) I suppose it's possible you melted the new cats, but I doubt that if you just picked up the car and drove it home. If you drove it for a hundred miles with the CEL flashing then maybe.

[Breeves002]

I don't think he said he had the muffler replaced. Cut it off and see what happens!

That is correct though. Should have no EGR flow at idle.


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[SES Dad]

Thanks guys. But yes, ALL exhaust components were replaced, including the muffler.
Could there be a clog at the exhaust manifold on that side?
I've got lots of pressure, even at idle, on the downstream (closest to the cat) nipple on the EGR tube.
Should the next move be to return it to my exhaust shop?
No missing of the engine nor flashing CEL. I think this 'clog' issue was thought to be a miss by my exhaust guy.
Anything I can check in my garage?

[Breeves002]

Personally I would bring it back to the exhaust shop. I'm confused though - you say you have good exhaust flow right? Wonder where the restriction is happening.


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[SES Dad]

Don't necessarily know what 'good flow' is. Before I had everything replaced, there was nothing. Still showed the same 'blowing' at the EGR tube. It sounds exactly the same.
Also, power and restriction gets worse after the engine warms up.
I am truly confused by this one.