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NEW CODE (P420) PLEASE HELP


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ok. lat thursday i had a alittl eissue with my car. i had to do some errands and when i came back to turn it on...it did some weird noise and it felt like it was going to turn off....i tried to drive it home..and it just seemed it was loosing too much horse power..the more i would step on the gas the slower it would go....after i got home...i turned it off and turned it back again...and i could smell a funy smell like if rubber was burning........on friday my car ran fine..up until yesturday...it started doing the same thing..when i looked under the car i could see smoke coming out fromt he catalyc converter...and i still had the same symptoms...the car would stall alot. i ran the codes and these are the one dat showed up (p420; p741; p1574; p1860)

im not really concerned about the (p1860 or p741) becaus eive had them for about 1 year and i had no problems with it.....the newest code i received was the p420......i've been reading online and people say it might be a bad cat and needs to be replaced and so on.........

can any one please help me..........im going to be changing the new spark plugs today..i hope that makes a difference.

thanks soo much

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I would suggest going to a different gas station, assuming you usually fill-up at the same station. The P420 code can indicate a bad catalytic converter, however, I have read where this should not effect the engine. It may, however, cause an oxygen sensor to fail if there is too much pollutants in the exhaust--If you have an O2 sensor on or in the path of the catalytic converter, it could possibly be going bad? But if it was, a code should set. The P420 codes will set if the oxygen sensor output is outside of acceptable parameters. Also, if you have any leak in the exhaust system, repair it!

Here is one way to determine if the catalytic converter is bad:

Measure the inlet and outlet external temperatures of

the catalytic converter with a thermometer capable

of reading up to 500°F.

• If the outlet temperature is more than 100°F hotter

than the inlet temperature, the converter is OK;

clear the DTC, and return the vehicle to the

customer.

• If the outlet temperature is less than 100°F hotter

than the inlet temperature, replace the converter.

This is one generally accepted way to get an idea if the converter is bad. If the temperature is 200 degrees or more hotter on the outlet side then the engine is running too rich. Look at the converter itself and see if the shell is warped or discolored due to excessive heat. This will give you an indication if there is a fuel metering problem.

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ok i changed the spark plugs and some had some oil on the thread. they were also gaped at .40 ...when i first bought them, the guy from autozone told me they were already gapped. so i took his word. i was wrong. the correct gap size was .50 do you guys think that might be the problem too????????

post-10243-1251401477_thumb.jpg

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I would suggest going to a different gas station, assuming you usually fill-up at the same station. The P420 code can indicate a bad catalytic converter, however, I have ready where this should not effect the engine. It may, however, cause an oxygen sensor to fail if there is too much pollutants in the exhaust--If you have an O2 sensor on or in the path of the catalytic converter, it could possibly be going bad? But if it was, a code should set. The P420 codes will set if the oxygen sensor output is outside of acceptable parameters. Also, if you have any leak in the exhaust system, repair it!

Here is one way to determine if the catalytic converter is bad:

Measure the inlet and outlet external temperatures of

the catalytic converter with a thermometer capable

of reading up to 500°F.

• If the outlet temperature is more than 100°F hotter

than the inlet temperature, the converter is OK;

clear the DTC, and return the vehicle to the

customer.

• If the outlet temperature is less than 100°F hotter

than the inlet temperature, replace the converter.

This is one generally accepted way to get an idea if the converter is bad. If the temperature is 200 degrees or more hotter on the outlet side then the engine is running too rich. Look at the converter itself and see if the shell is warped or discolored due to excessive heat. This will give you an indication if there is a fuel metering problem.

how do i test the temperature?? what do i need???

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I would suggest going to a different gas station, assuming you usually fill-up at the same station. The P420 code can indicate a bad catalytic converter, however, I have ready where this should not effect the engine. It may, however, cause an oxygen sensor to fail if there is too much pollutants in the exhaust--If you have an O2 sensor on or in the path of the catalytic converter, it could possibly be going bad? But if it was, a code should set. The P420 codes will set if the oxygen sensor output is outside of acceptable parameters. Also, if you have any leak in the exhaust system, repair it!

Here is one way to determine if the catalytic converter is bad:

Measure the inlet and outlet external temperatures of

the catalytic converter with a thermometer capable

of reading up to 500°F.

• If the outlet temperature is more than 100°F hotter

than the inlet temperature, the converter is OK;

clear the DTC, and return the vehicle to the

customer.

• If the outlet temperature is less than 100°F hotter

than the inlet temperature, replace the converter.

This is one generally accepted way to get an idea if the converter is bad. If the temperature is 200 degrees or more hotter on the outlet side then the engine is running too rich. Look at the converter itself and see if the shell is warped or discolored due to excessive heat. This will give you an indication if there is a fuel metering problem.

how do i test the temperature?? what do i need???

Here is a one example of a thermometer by Raytek.

If you can loosen the exhaust pipe (not totally disconnect) before the catalytic converter then you may be able to relieve backpressure that is building up. If you do it right, and the engine is no longer struggling, it may also be a way to verify that the catalytic converter is clogged.

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I would suggest going to a different gas station, assuming you usually fill-up at the same station. The P420 code can indicate a bad catalytic converter, however, I have ready where this should not effect the engine. It may, however, cause an oxygen sensor to fail if there is too much pollutants in the exhaust--If you have an O2 sensor on or in the path of the catalytic converter, it could possibly be going bad? But if it was, a code should set. The P420 codes will set if the oxygen sensor output is outside of acceptable parameters. Also, if you have any leak in the exhaust system, repair it!

Here is one way to determine if the catalytic converter is bad:

Measure the inlet and outlet external temperatures of

the catalytic converter with a thermometer capable

of reading up to 500°F.

• If the outlet temperature is more than 100°F hotter

than the inlet temperature, the converter is OK;

clear the DTC, and return the vehicle to the

customer.

• If the outlet temperature is less than 100°F hotter

than the inlet temperature, replace the converter.

This is one generally accepted way to get an idea if the converter is bad. If the temperature is 200 degrees or more hotter on the outlet side then the engine is running too rich. Look at the converter itself and see if the shell is warped or discolored due to excessive heat. This will give you an indication if there is a fuel metering problem.

how do i test the temperature?? what do i need???

Here is a one example of a thermometer by Raytek.

If you can loosen the exhaust pipe (not totally disconnect) before the catalytic converter then you may be able to relieve backpressure that is building up. If you do it right, and the engine is no longer struggling, it may also be a way to verify that the catalytic converter is clogged.

i will definitly try it. but for some reason it only happens once in a while......this morning when i was leaving to work the car was fine. its not like its happening every time i drive my car or it happends every time i turn it on.. thats the weird thing about it.

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