Kenny Lee Posted September 29, 2015 Report Share Posted September 29, 2015 2002 Seville SLS with 220,000 miles. Good starting and idlling, but I try to accelate it, it never goes over 2,000 rpm. And not more than 20 seconds it drops down to 500 rpm automatically or stops with trembling. My struggles for..... 1. replace fuel pump and fuel filter. 2. replace secondary air injection hose assembly (none when I buy my car) 3. cleaning and checking eletronic EGR valve, and it works smoothly. 4. checking and cleaning Mass Air Flow sensor. It is clean. 5. cleaning air intake cabulator with cleaning spray and soft cloth. There was a lot of carbon. 6. There was 'check engine soon' sign, so checking my Caddy's Info Center. there is P0403 code only. 7. After I deleted all codes in Info Cenetr, 'Check engine' sign has gone. 8. No bubbling in coolant reservoir. Excess high temperature in cooling system I guess. But Temp. guage is in normal. 9. Still I can hear the noisy sound and some smoke in bumper area of driver side when I accelate. (I am doubt of abnormal secondary air injection pump.) 10. Anyway......2,000 rpm limitation exists. What should I do next? Link to comment Share on other sites More sharing options...
Bruce Nunnally Posted September 29, 2015 Report Share Posted September 29, 2015 Welcome; do you know what codes there were? Bruce 2023 Cadillac CT4-V Blackwing Follow me on: Twitter Instagram Youtube Link to comment Share on other sites More sharing options...
barczy01 Posted September 29, 2015 Report Share Posted September 29, 2015 exhaust restriction.. In a perfect world, unbolt the 4 13mm nuts from the exhaust flange and go for a ride. Link to comment Share on other sites More sharing options...
rockfangd Posted September 29, 2015 Report Share Posted September 29, 2015 same here. Plugged cat. Does it ever smell like hot metal or anything weird? GM FAN FOREVER Nice, clean, luxury= fine automobile Link to comment Share on other sites More sharing options...
Kenny Lee Posted September 29, 2015 Author Report Share Posted September 29, 2015 To Bruce According to Info center, lots of code history exist. But, current code was only P 0403. Engine-codes.com said.... Possible causes - EGR volume control valve stuck open or closed- Faulty EGR volume control solenoid valve- EGR volume control solenoid valve harness is open or shorted- EGR volume control solenoid valve circuit poor electrical connection- EGR temperature sensor and circuit When is the code detected? An improper voltage signal is sent to Powertrain Control Module (PCM) through the valve Possible symptoms - Engine Light ON (or Service Engine Soon Warning Light)- Possible engine hesitation Link to comment Share on other sites More sharing options...
Kenny Lee Posted September 29, 2015 Author Report Share Posted September 29, 2015 To barczy01 I will try it as soon as possible, and post the result of your recommendation ! Appreciate very much. Link to comment Share on other sites More sharing options...
Kenny Lee Posted September 29, 2015 Author Report Share Posted September 29, 2015 To rockfangd It smells like oil burning first. Hot metal??? Ummm....maybe?! Link to comment Share on other sites More sharing options...
Kenny Lee Posted September 29, 2015 Author Report Share Posted September 29, 2015 To barczy01 According to this diagram, No.12 Exhaust Pipe No.13 Exhaust Flange No.16 Converter, Catalytic Converter No.20 Bolt Your advice means unpluging four 13 mm nuts (No.20), doesn't it? Just loosen them? Link to comment Share on other sites More sharing options...
barczy01 Posted September 29, 2015 Report Share Posted September 29, 2015 The picture above looks nothing like a cadillac exhaust. Stand next to the drivers door then look underneath the car in that location. You will see a square flange, that's where the exhaust is split, 4 13mm nuts. Link to comment Share on other sites More sharing options...
BodybyFisher Posted September 29, 2015 Report Share Posted September 29, 2015 Yep, 2002 was a bad year for CATS.... exhaust restriction. There is a backpressure gauge you can buy that screws into the O2 sensor port that will confirm the backpressure see it here http://www.amazon.com/Tool-Aid-33600-Exhaust-Pressure/dp/B0002SQW9S We have had a lot of 2002s with bad cats, my 2002 monte carlo was power limited and bearly moved, bad cat 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 Link to comment Share on other sites More sharing options...
BodybyFisher Posted September 29, 2015 Report Share Posted September 29, 2015 Just saw that you have a P0403 also, EGR malfunction, as you know holding an egr open will stall the engine. How does it idle?, normal idle? It certainly seems to be a clogged cat but you need to get that check engine light out by fixing the EGR issue. The engine management system will remain in open loop and the fuel mixture will be rich. The rich mixture will quickly destroy your CATS. Fix that P code and get the CEL out asap You deleted the P0403 code but my guess is it will return over the next couple of days as the management system goes through a drive cycle. Next time you see it take note as to whether the code is current or history Events that stop the engine management system from going into closed loop must be fixed promptly. Constant rich mixtures destroy O2 sensors and cats not to mention hurt gas mileage 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 Link to comment Share on other sites More sharing options...
rockfangd Posted September 29, 2015 Report Share Posted September 29, 2015 IIRC plugged cat causes egr issues also, It has to go somewhere GM FAN FOREVER Nice, clean, luxury= fine automobile Link to comment Share on other sites More sharing options...
BodybyFisher Posted September 29, 2015 Report Share Posted September 29, 2015 Yes that is possible but the code relates to the control circuit. http://www.gmforum.com/obd-ii-trouble-shooting-153/p0403-284085/ 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 Link to comment Share on other sites More sharing options...
James Woods Posted October 1, 2015 Report Share Posted October 1, 2015 The secondary air wouldn't affect driveability after a cold start up. Its purpose is to supply extra air into the cylinders to compensate for rich circuit until engine leans out. Normal runtime is about 30-45 second . Now an valve for the air injection stuck open did draw in excess air even with the secondary air pump off. But that would be showing a lean code. I agree with check for a plugged or excessive back pressure exhaust.and also taking care of the EGR code to enable engine to go to open loop. Good luck Link to comment Share on other sites More sharing options...
Kenny Lee Posted October 2, 2015 Author Report Share Posted October 2, 2015 Thank you all guys!! To Bruce, rockfangd, BodybyfFisher, Jwoods016 and especially barczy01 !! My problem was excessive back pressure exhaust. According to your advices, I unbolt the four 13mm nuts from the exhaust flange after WD-40 shower to them. In spite of thundering noise, engine runs very good~!! For another guy who should be suffered just like my case, I'd like to write down here some hints I found before fixing it 1. When I accelerate, there are noise and smoke on 'secondary air injection pump system' Now I understand the reason. Because of excessive back pressure exhaust, exhaust gas has flowed backward to pump assembly. 2. There was a bubbling in EGR system gasket. Same as above reason. Excessive pressure of exhaust gas Now I wonder how can I fix the excessive back pressure exhaust problem. If anybody has a economical advice, please tell me asap~!! Link to comment Share on other sites More sharing options...
Bruce Nunnally Posted October 2, 2015 Report Share Posted October 2, 2015 The catalytic converter uses a honeycomb core element. When the converter fails this honeycomb sometimes collapses and becomes blocked or clogged. Then the converter doesn't flow properly. To correct, replace the catalytic converter. An OEM exact match converter can be expensive but a less expensive generic is fine. In the mean time, people sometimes further break up and remove the honeycomb catalytic element from the converter shell allowing flow through the empty shell. This can cause a trouble light & DTC. The purpose of the catalytic converter is to oxidize CO to CO2, control nitrous oxide ouput, and to reduce certain hydrocarbons. The element itself is made of precious metals but should be treated as a bio-hazard due to being coated w exhaust emissions. Bruce 2023 Cadillac CT4-V Blackwing Follow me on: Twitter Instagram Youtube Link to comment Share on other sites More sharing options...
BodybyFisher Posted October 2, 2015 Report Share Posted October 2, 2015 You need a new CAT. If money is a problem try your local scrap yard. Try www.rockauto.com we probably have a 5% discount around here someplace. 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 Link to comment Share on other sites More sharing options...
rockfangd Posted October 2, 2015 Report Share Posted October 2, 2015 Just to note it is not legal to purchase a used cat. Not in NY anyway. The only way you can get a used one is if you know someone that has one and is willing to sell(give) it to you GM FAN FOREVER Nice, clean, luxury= fine automobile Link to comment Share on other sites More sharing options...
BodybyFisher Posted October 2, 2015 Report Share Posted October 2, 2015 Ohhh didnt know that, being in NY I should know that, good info 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 Link to comment Share on other sites More sharing options...
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