Not passing emissions with code P0700 and possible catalytic converter issue

Tiny
ANTOINE ANDERSON
  • MEMBER
  • 2012 CHEVROLET IMPALA
  • 6.0L
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 60,289 MILES
Well, the problem is the car was sitting for awhile for about a year and a half. Now I got it started with fluids in it it wouldn't go in reverse, so I added transmission fluid and then it started to go in reverse. But then I continue to drive it for a week or so and it wouldn't go in reverse again. So I added more fluid to it and then it went in reverse. Again I took it to get a smog check but it wouldn't pass. It was getting off a p0 700 code. I believe so they thought it was a transmission so I had to take it in for recall to get the ignition switch fixed. Once I did that I took it back again and it was not giving off any codes so the mechanic said he's pretty sure that is a catalytic converter and I told him that I heard some like noises crying around in there when I was driving and he said yeah she's pretty sure it is a catalytic converter. So at that time when I was driving home and I was driving uphill and it kind of like spoiled kind of like jumping back and forth as if it wasn't getting any power. So I'm trying to be sure that is the catalytic converter before I do anything else. Can you help me please?
Sunday, June 7th, 2020 AT 9:52 AM

5 Replies

Tiny
KASEKENNY
  • MECHANIC
  • 18,907 POSTS
My opinion is that you could have two issues. First did they smog test fail due to the P0700 or did it not pass the tailpipe emission output portion?

The P0700 is just basically an informational code telling you that you have a code in the transmission control module which would be related to the shifting feeling that you are getting driving down the road.

If the converters are clogged it could cause some driving issue but that is normally low power and not necessarily shifting issues.

So I suspect the vehicle failed the test due to the converters not reducing the emissions enough and then you are also experiencing a shifting issue which would be related to the transmission.

Do you have the test results from the smog test and have you actually checked for codes? There is a chance it failed the smog test due to the code they found but the P0700 is does not give us enough info to determine the issue. We need to check for all codes and if you can't scan for codes, then you can stop by a parts store and they should be able to pull all codes.

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing
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Sunday, June 7th, 2020 AT 1:31 PM
Tiny
STEVE W.
  • MECHANIC
  • 13,584 POSTS
As KASEKENNY1 said, P0700 is a transmission related code. Your description of a whine could easily be transmission damage from running it low on fluid, however you need to first figure out where the fluid is going. As far as the smog check, if it is burning transmission fluid it wouldn't pass, and in many states if the CEL is on or if there is a code to turn it on (pending code) it will fail. I would start by pulling all the codes. Then post them all here.
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Sunday, June 7th, 2020 AT 2:01 PM
Tiny
ANTOINE ANDERSON
  • MEMBER
  • 3 POSTS
Yeah, but there were a few times that I got it in the morning and tried to start it and it wouldn't start. And also the guy said it was a catalytic converter because I got in a couple of times in the morning and it will not start. I had to turn the key two times.
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Sunday, June 7th, 2020 AT 2:08 PM
Tiny
ANTOINE ANDERSON
  • MEMBER
  • 3 POSTS
And after I took it into the dealer to have the ignition switch repaired because it was a recall on it the transmission code went off.
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Sunday, June 7th, 2020 AT 2:12 PM
Tiny
STEVE W.
  • MECHANIC
  • 13,584 POSTS
A bad catalytic converter wouldn't cause it to not start like that. However, having the transmission range control out of position or the interlock in the steering column wrong could. What does it do when it won't start, turn over but not fire? Turn over slow? Not turn at all?
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Sunday, June 7th, 2020 AT 3:33 PM

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