: Codes, 0401, 0420, 0300, 0440



TEXASROCKS
04-07-10, 08:36 PM
Hi all, i'm new to the group, and i have a few questions.

i got my 98' Deville, checked for codes the other day due to the "service engine soon" light being on, and there were multiple codes that came up...0401 (egr), 0420 (bank 1 O2), 0300 (random misfire), and 0440 (evap emission sys)...can anyone tell me the first things to check...meaning the cheapest things to check hehe. The car does run good...its just hard starting now and again, but when it starts it smells like it was flooded...runs rough for a few seconds and then smooths out. It also emits some black smoke when it shifts down. Its gets good mileage on the hwy as well so i'm kind of confused about what could be causing these issues :hmm:

Thanks for reading and hope everyones well!

Ranger
04-07-10, 09:06 PM
0440 (evap emission sys)
Check the gas cap and be sure that it is on tight (ratchets). If that is OK, then look for a vacuum leak on the vent line from the tank to the EVAP solenoid/valve or from there to the fuel vapor canister.

when it starts it smells like it was flooded...runs rough for a few seconds and then smooths out. It also emits some black smoke when it shifts down.

Check for a leaky FPR. Small canister on the fuel rail. Pull the vacuum line (red arrow) off at idle. If there is any fuel present, replace it. There should be none.

TEXASROCKS
04-07-10, 09:51 PM
Thanks Ranger, checked the cap and it seems to be on tight, i'll have to check the vent line tomorrow. As for the FPR there was fuel in that vac. line because i broke it by accident while pulling the EGR to clean it. I know you should check it while it is at idle but but after it broke there was a bit of fuel dripping out of that vac. line so i'm assuming a new FPR is in order??

Ranger
04-07-10, 10:01 PM
Yup. Any fuel in that line at any time means that the diaphragm in the FPR that separates the fuel side from the vacuum side has ruptured and you are sucking unmetered fuel into the manifold, thus running rich. Fix that first, then clear all the DTC's and see if any return.

TEXASROCKS
04-12-10, 07:36 PM
Thanks for the info Ranger, been a little while but i have yet to pull the regulator due to a shortage of $ but hopefully it solves the prob!

Submariner409
04-13-10, 09:14 AM
www.rockauto.com, surf to your car, fuel/air, fuel injection pressure regulator, DELPHI, $42.79.