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-   -   Smog problem (https://www.rx7club.com/3rd-generation-specific-1993-2002-16/smog-problem-1172772/)

despistao Mar 19, 2026 08:11 AM

Smog problem
 
I'm having this problem and they're blocking my emissions test. The engine was recently rebuilt (less than 10 miles, the car has barely been driven).

Everything is OEM except the EGR, which is disabled with a plate. It's giving me error code 16. I read about the mod using a relay to trick the ECU with the EGR, and I'll do that.

The air pump is working correctly.

Could it be due to insufficient mileage after the rebuild?
Clogged catalytic converters?
13.6 of AFR at idle (very high).

We noticed that there was no plug in one of the upper intake ports.

There's no filter before the MAP sensor,could this be affecting it?

ptrhahn Mar 19, 2026 01:03 PM

What are the actual emissions test results for various parameters? Tough to diagnose a simple non-passage.

despistao Mar 19, 2026 03:18 PM


Originally Posted by ptrhahn (Post 12650839)
What are the actual emissions test results for various parameters? Tough to diagnose a simple non-passage.

CO engine idling 5,45% ( 0,5% max)
CO accelerated idle 2,12% ( 0,3% max)
lambda 0,939 (AFR 13.3)

gracer7-rx7 Mar 23, 2026 12:11 PM

I personally can't help diagnose this but arghx posted some really insightful information on emissions system and some troubleshooting in old threads. See the links in the FAQ https://www.rx7club.com/3rd-generati...l-links-68640/

DaveW Mar 23, 2026 03:40 PM


Originally Posted by despistao (Post 12650843)
CO engine idling 5,45% ( 0,5% max)
CO accelerated idle 2,12% ( 0,3% max)
lambda 0,939 (AFR 13.3)

Not that I'm an expert on emissions, but these CO numbers sound like the cat(s) is/are dead - catalysts gone or coated with lead, etc.

despistao Mar 23, 2026 04:52 PM


Originally Posted by gracer7-rx7 (Post 12651041)
I personally can't help diagnose this but arghx posted some really insightful information on emissions system and some troubleshooting in old threads. See the links in the FAQ https://www.rx7club.com/3rd-generati...l-links-68640/

Thanks for the link.

I'm actually familiar with many of the posts; I even read a post about the smog problems a forum member had in California.

despistao Mar 23, 2026 04:57 PM


Originally Posted by DaveW (Post 12651052)
Not that I'm an expert on emissions, but these CO numbers sound like the cat(s) is/are dead - catalysts gone or coated with lead, etc.

That's what I'm thinking.
The air pump is working correctly, the EGR is disabled because it was giving me error code 16.

I bought a Magnaflow catalytic to replace the OEM .
The car is running very rich, so I'm thinking it's the catalytic . New spark plugs, maybe spark plug wires? stable idle

gracer7-rx7 Mar 25, 2026 11:48 AM

are you running the stock ecu? I can't imagine it running richer than required. Which makes me think there could be another problem causing you to run rich. Do you have a wideband to confirm your car is running rich or are you judging by smell? If the cat is not working properly, it will probably smell more.

despistao Mar 25, 2026 01:10 PM


Originally Posted by gracer7-rx7 (Post 12651171)
are you running the stock ecu? I can't imagine it running richer than required. Which makes me think there could be another problem causing you to run rich. Do you have a wideband to confirm your car is running rich or are you judging by smell? If the cat is not working properly, it will probably smell more.

No, I don't have a wideband, the AFR reading is what's shown in the emission test

Yes, I'm running an stock ECU. I'm trying to figure out it's a problem with the cat , and that when error code 16 (EGR) pops up, the ECU goes into some kind of mode.

I've borrowed a PFC, and with the base map, everything seems fine, although nothing has been tuned. No more error codes are appearing (obviously).

I'm also going to change the coil wires.

I don't know whether to try to pass the emissions test with the PFC kit, or do the 12V relay mod and use the stock ECU.

gracer7-rx7 Mar 25, 2026 04:42 PM

Ah, I see. 13-ish AFR isn't too rich for the RX7 at idle. I think that is normal. A better course of action is to troubleshoot your EGR issue.

Regarding the PFC, it has some good diagnostic options in that you can potentially use to help troubleshoot but it is not tuned to pass emissions tests like the stock ECU.

despistao Mar 25, 2026 05:22 PM


Originally Posted by gracer7-rx7 (Post 12651189)
Ah, I see. 13-ish AFR isn't too rich for the RX7 at idle. I think that is normal. A better course of action is to troubleshoot your EGR issue.

Regarding the PFC, it has some good diagnostic options in that you can potentially use to help troubleshoot but it is not tuned to pass emissions tests like the stock ECU.

I performed this mod, but it's still giving me an error... I don't know if I connected the relay poles incorrectly.

https://www.rx7club.com/3rd-generati...ix-egr-345468/


Any pointers on how to fine-tune the PFC? I've been searching for quite a while and haven't been able to find a manual


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