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P0410... again.


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**I'm sorry, This is a 2002 Deville and I meant to post in the Deville section.**

I need some help here. (I'm re posting about a reoccurring problem). I ran for about 500 miles after a clean bill of health and a passing emission test & NO codes. (never without the "shutter" feeling stated in previous post)

The SES light is NOT on, BUT a code has finally appeared. P0410. [Good news is the smog pump is new and has not gotten wet again since its installation]

So what other components should I be looking at and how can I isolate this? (the pump was full of water when I replaced it so I know it was a problem. and the code went away for 500+ miles since)

I have pulled my coils and plugs and they all look to be firing OK. I spent a day underneath tightening every nut and bolt. (almost felt like a loose motor mount but they were fine)

I feel it most drastically around town when I let off the gas pedal or accelerate modestly. OR when it's on cruise control and it accelerates / decelerates on its own. Shutter seems to disappear when driving hard or in 2nd.

(Time-certed motor, new motor mounts, torque conv., TCC, 2nd air inj pump, cat convertor...I've owned this 6 months)

(I know I could have bought 1/2 a CTS-V by now! Help me out here?)

Ask me anything I'll tell you no lies here. Tell me where to look or what to try and I'm game. I fear I need to bring this to a dealer and pay them to diagnose and repair. (O sin of sins)

Edited by 94pain
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Do you hear the AIR pump motor actually COME ON when you do a clod start??

If you hear the motor, inspect the components that control the Air delivery such as the Check Valve Solenoid, the Check Valve and the rubber hoses, metal piping and passages.

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Do you hear the AIR pump motor actually COME ON when you do a clod start??

If you hear the motor, inspect the components that control the Air delivery such as the Check Valve Solenoid, the Check Valve and the rubber hoses, metal piping and passages.

The motor sounds a little like an airplane wirrrring. Yes, it's there. How can I test the Check Valve Solenoid? and do I just disconnect and physically inspect the metal passages and piping?

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The motor sounds a little like an airplane wirrrring. Yes, it's there. How can I test the Check Valve Solenoid? and do I just disconnect and physically inspect the metal passages and piping?

I have no DIRECT EXPERIENCE with the AIR system...so take what I say and know I might be mistaken

Check the fuses for the AIR system first... if they are OK...

From my reading about the AIR system... the metal tubing can get clogged up with carbon.

The check valve is a ONE WAY valve that should only let air flow one way and then only at certain times, like during the initial cold start sequence.

There should be voltage going to the solenoid during air pump operation to open the check valves...

Also be sure to check all the rubber hoses for any restrictions or leaks..

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I will do my best to disassemble and inspect these components today then post back.

I noticed that when driving down hill in neutral the car gains speed. I repeated this and the car definitely seems "bogged" down a little. It actually slows down 1-2 mph when going down a hill in drive.

Don't know if this adds anything for diagnosis but it explains the 12-13 mpg around town. BUT still gets 27-30mpg highway.

Also, the car starts up perfectly smooth, and kicks down to 625-650 rpm in 60 seconds or so. No unusual noises besides the pump wirrring. Sometimes when it is well warmed up it wont start on 1st try. 2nd turn always starts it. (but this is only one out of fifty starts and only when the engine is well heated)

Edited by 94pain
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That 12 to 13 around town is normal, and I doubt its related to this code

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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Here is a little more info on the solenoid troubleshooting...

If the pump sounds OK when it is running, check the AIR solenoid for passing air through when energized, this solenoid is only energized when the pump runs.

If no air is passing through the AIR solenoid, check the power to the solenoid on the Pink and Black wire and a good ground on the Black wire.

If no voltage is found on the Pink and Black wire when the pump is energized, check the AIR solenoid fuse

If the fuse if OK, and the ground is OK, but the solenoid will not pass air through it, the solenoid will need to be replaced.

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It may seem a little late to ask this but, does this pump only run at start up? I can hear it making a jet engine wirrrring sound whenever I'm driving around.

Is this usual? It has been making this sound since it was installed 5-600 miles ago. (it is the replacement with the snorkel intake hose)

The SES light went off and it passed emissions so I figured the sound was that of success?

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It may seem a little late to ask this but, does this pump only run at start up? I can hear it making a jet engine wirrrring sound whenever I'm driving around.

Is this usual? It has been making this sound since it was installed 5-600 miles ago. (it is the replacement with the snorkel intake hose)

The SES light went off and it passed emissions so I figured the sound was that of success?

My understanding is the pump is only supposed to run for a short time and only on a cold start...

But I am not 100% totally sure of that...

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"My understanding is the pump is only supposed to run for a short time and only on a cold start...

But I am not 100% totally sure of that..."

I just took her out for a run. It's warmed up to half temp., and definitely wirrrring away... so I guess I gotta ask... Is that a problem?!

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The internet is out at my house because of the storms last night so I gotta post a couple questions and check back in the morning.

1. I hate to spend the money but if I brought this to a dealership can they diagnose this with better testing equipment than I have or would they just install parts till they fix it?

2. How do you guys do that cool little quote in a box thing when you re-post? I just cut n paste.

Thank you so much for all the help you've given me. I love my Caddy but I'm hemorrhaging money and I still don't feel safe enough to take a vacation without it breaking down somewhere.

I promise to re post what it was when i find the cure... thanks.

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"My understanding is the pump is only supposed to run for a short time and only on a cold start...

But I am not 100% totally sure of that..."

I just took her out for a run. It's warmed up to half temp., and definitely wirrrring away... so I guess I gotta ask... Is that a problem?!

I wish you had went a few more blocks to get it all the way up to normal temperature. :) :)

Like I said.... I have never personally had one act up, so I am just going by what I have read about the AIR System.

The pump works when it is cold... before the engine warms up.

It pumps extra air into the exhaust manifolds to dilute the rich mixture that the engine has when below normal temps.

The code sets when the o2 sensor voltage does not drop when the air pump is running...

Based on my reading... it should stop running when the engine warms up...

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The internet is out at my house because of the storms last night so I gotta post a couple questions and check back in the morning.

1. I hate to spend the money but if I brought this to a dealership can they diagnose this with better testing equipment than I have or would they just install parts till they fix it?

2. How do you guys do that cool little quote in a box thing when you re-post? I just cut n paste.

Thank you so much for all the help you've given me. I love my Caddy but I'm hemorrhaging money and I still don't feel safe enough to take a vacation without it breaking down somewhere.

I promise to re post what it was when i find the cure... thanks.

To answer your first question...That depends on the dealer...

Some are very good at testing, and some are completely terrible... they just throw parts at it till they think it is fixed or your money runs out....

There is actually a FLOW CHART for them to use when testing it which should pinpont the problem.

Your second question....

Click on the "REPLY" button on the lower right...

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I wish you had went a few more blocks to get it all the way up to normal temperature. :) :)

Your second question....

Click on the "REPLY" button on the lower right...

Jim,

Thank you.

And Thank you.

Not sure if the first was a joke... but by "half way" temperature you understand- halfway on the gauge. It never goes higher unless there's a problem or I've been doing a WOT.

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I wish you had went a few more blocks to get it all the way up to normal temperature. :) :)

Your second question....

Click on the "REPLY" button on the lower right...

Jim,

Thank you.

And Thank you.

Not sure if the first was a joke... but by "half way" temperature you understand- halfway on the gauge. It never goes higher unless there's a problem or I've been doing a WOT.

Yep... I misunderstood you....

I thought you meant HALFWAY WARMED UP.... :D :D

Not halfway up on the gauge... which is normal temp.

Maybe someone else will jump in after a bit, and add something that I have missed...

I feel like I am missing telling you something but I can;t think of what it is...

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Hey guys,

I'm happy to report I found a cracked /disconnected vacuum hose that was the P0420. Code gone for 100+ miles. Easy stuff.

Problem: I'm still stuck with a poor running Caddy with NO codes to go on. I've been through all the fuses, they're fine. Plugs look good, they're new. The coils I can't tell about... plugs look worked... Wouldn't OBD show a code if a coil were bad?

I think I'm gonna break down and bring her in for the dealership "cou de gras". Any suggestions on how a can test coils? (besides swapping them out)

Also- The corner on the aluminum on the coil plate is snapped off on both heads. (I know it doesn't effect performance- but god it pisses me off when I take such good care of my stuff to have the motor swap guy snap them, prying 'em off, and tell me "it doesn't effect the performance")

(Know what I mean here? Should Do you insist they replace them??)

I loathe dealership prices but applaud their professionalism.

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did they replace the connector on the air pump? I recall its just has 1 air pump..yea?

Not sure what you mean.

There is only one pump unit on the 2002, yes, and it is a self contained piece with a re designed hose that climbs up further and clips into a fender hole to pull its air from inside the engine compartment and reduce the chances of future water intake.

** Caution: I've read other posts referring to it's plugging into the air box. On my car it just pops through the fender wall and would have to be covered or plugged if you wash / hose out the engine compartment as it is still exposed.

The wire plug / connector was reused but the hose clamps come new with the replacement unit, so not sure what you mean.

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