# 98 toyota camry emissions night mare **URL:** \ **Category:** Maintenance/Repairs\ **Tags:** emissions, engines, toyota, camry\ **Created:** [April 13, 2020, 11:00pm UTC](https://community.cartalk.com/t/98-toyota-camry-emissions-night-mare/162807 "2020-04-13T23:00:29Z")\ **Posts on this page:** 17\ **Page:** 1
**Author:** ![Rob\_Rogers1](https://avatars.discourse-cdn.com/v4/letter/r/bcef8e/32.png) [@Rob\_Rogers1](https://community.cartalk.com/u/Rob_Rogers1)\ **Post date:** [April 13, 2020, 11:00pm UTC](https://community.cartalk.com/t/98-toyota-camry-emissions-night-mare/162807/1 "2020-04-13T23:00:29Z")
have a 98 toyota camry with the 4cyl automatic and im haveing a helluva time with emissioms have replaced all emissions components mechanical and electric from charcoal canister to egr valve and all switches and switching valves in between and i am still getting codes P0401 and P0402 …Help!!! ---
**Author:** ![NYBo](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/nybo/32/17281_2.png) [@NYBo](https://community.cartalk.com/u/NYBo)\ **Post date:** [April 13, 2020, 11:12pm UTC](https://community.cartalk.com/t/98-toyota-camry-emissions-night-mare/162807/2 "2020-04-13T23:12:28Z")
Welcome to Car Talk! Did you clean out or replace the EGR plumbing and ports? ---
**Author:** ![Barkydog](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/barkydog/32/2470_2.png) [@Barkydog](https://community.cartalk.com/u/Barkydog)\ **Post date:** [April 13, 2020, 11:13pm UTC](https://community.cartalk.com/t/98-toyota-camry-emissions-night-mare/162807/3 "2020-04-13T23:13:40Z")
I think in our state you can get a waiver after spending so many dollars. ---
**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\ **Post date:** [April 13, 2020, 11:29pm UTC](https://community.cartalk.com/t/98-toyota-camry-emissions-night-mare/162807/4 "2020-04-13T23:29:28Z")
Have you tested/replaced the EGR vacuum modulator? ![](https://global.discourse-cdn.com/cartalk/original/3X/2/0/205be724fde93e195ebfbda54e1eb261e353fa60.jpeg) This is what controls the operation of the EGR valve. Tester ---
**Author:** ![jdmere](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/jdmere/32/3002_2.png) [@jdmere](https://community.cartalk.com/u/jdmere)\ **Post date:** [April 13, 2020, 11:36pm UTC](https://community.cartalk.com/t/98-toyota-camry-emissions-night-mare/162807/5 "2020-04-13T23:36:42Z")
P0402 usually involves the O2 sensors or the catalytic converter. What has been done with them? ---
**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\ **Post date:** [April 13, 2020, 11:38pm UTC](https://community.cartalk.com/t/98-toyota-camry-emissions-night-mare/162807/6 "2020-04-13T23:38:48Z")
> [@jdmere](#): > > P0402 usually involves the O2 sensors or the catalytic converter > **[P0402 Diagnostic Code - Trouble Code Diagnosis Guide | Toyota Parts Center](https://parts.olathetoyota.com/p0402-code-toyota)** > > P0402 Is The Exhaust Gas Recirculation Flow Excessive Flow Detected Code, And It's Basically The Opposite Of A P0401 Code. Tester ---
**Author:** ![Honda-Blackbird](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/honda-blackbird/32/3159_2.png) [@Honda-Blackbird](https://community.cartalk.com/u/Honda-Blackbird)\ **Post date:** [April 14, 2020, 12:42am UTC](https://community.cartalk.com/t/98-toyota-camry-emissions-night-mare/162807/7 "2020-04-14T00:42:56Z")
Sorry to hear that you or someone else “shotgunned” this repair I dont see it listed so i shall ask… did you replace the VSV ? Variable switching valve… it is well known to cause 401/2 codes and is often overlooked or mistakenly replaced with inferior aftermarket vsv units… it needs to be an OEM Toyota part. I believe it supplies varying levels of vacuum to the egr system or the egr itself… i forget. Cheap copies arent able to vary with the accuracy of the oem units…and wind up supplying too much or too little… when “just right” was needed. Many times they will cause the engine to stall bec they peg the egr open when its only sup to he partially open. Anywho… I just had a rash of 97-99 4cyl Camry’s all with 40x codes… and on all of them the solution was a new Toyota oem VSV… This was the solution 3 out of 3 times…after of course verifying all other components that were in play like the EGR and vac hoses etc. This valve is very often overlooked and to be honest i was well UNaware of its existence until a bunch of 4 cyl Camry’s decided to come to me all with 40x codes… The valve is a proper PIA to get to and when replacing it check all the rubber vac lines or simply replace all the lines to be sure they good…oem quality vac lines will last like no other as there is a vast difference in rubber quality in hoses… cheap hoses use cheap materials… just fyi But that is what i have found solved the issue. Unfortunately after “shotgunning” anything… you honestly dont know “where you are at” with the repair… but if u did NOT replace the vsv… i strongly suggest you look into it. ---
**Author:** ![Honda-Blackbird](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/honda-blackbird/32/3159_2.png) [@Honda-Blackbird](https://community.cartalk.com/u/Honda-Blackbird)\ **Post date:** [April 14, 2020, 12:47am UTC](https://community.cartalk.com/t/98-toyota-camry-emissions-night-mare/162807/8 "2020-04-14T00:47:26Z")
420 is the code that brings the cat and o2’s into play… not 401/2 i think you got the digits switched up from memory. Lol. Happens to me all the time ---
**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\ **Post date:** [April 14, 2020, 12:50am UTC](https://community.cartalk.com/t/98-toyota-camry-emissions-night-mare/162807/9 "2020-04-14T00:50:20Z")
??? Read my response? Tester ---
**Author:** ![Honda-Blackbird](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/honda-blackbird/32/3159_2.png) [@Honda-Blackbird](https://community.cartalk.com/u/Honda-Blackbird)\ **Post date:** [April 14, 2020, 12:53am UTC](https://community.cartalk.com/t/98-toyota-camry-emissions-night-mare/162807/10 "2020-04-14T00:53:19Z")
LOL… NO … what i just did was read what you quoted as if you responded. Omg im losing it…or my vision or both. Disregard Mr @Tester… I’m just flaking out It did seem odd that you would suggest what i thought u suggested… i did think that… but those werent your words at all Ok im goin to bed ---
**Author:** ![Rob\_Rogers1](https://avatars.discourse-cdn.com/v4/letter/r/bcef8e/32.png) [@Rob\_Rogers1](https://community.cartalk.com/u/Rob_Rogers1)\ **Post date:** [April 14, 2020, 2:22am UTC](https://community.cartalk.com/t/98-toyota-camry-emissions-night-mare/162807/11 "2020-04-14T02:22:39Z")
p0402 is excessive air flow ---
**Author:** ![Rob\_Rogers1](https://avatars.discourse-cdn.com/v4/letter/r/bcef8e/32.png) [@Rob\_Rogers1](https://community.cartalk.com/u/Rob_Rogers1)\ **Post date:** [April 14, 2020, 2:25am UTC](https://community.cartalk.com/t/98-toyota-camry-emissions-night-mare/162807/12 "2020-04-14T02:25:24Z")
my year doesnt have a DPFE ---
**Author:** ![Rob\_Rogers1](https://avatars.discourse-cdn.com/v4/letter/r/bcef8e/32.png) [@Rob\_Rogers1](https://community.cartalk.com/u/Rob_Rogers1)\ **Post date:** [April 14, 2020, 2:26am UTC](https://community.cartalk.com/t/98-toyota-camry-emissions-night-mare/162807/13 "2020-04-14T02:26:45Z")
no p0401 and p0402 ---
**Author:** ![Rob\_Rogers1](https://avatars.discourse-cdn.com/v4/letter/r/bcef8e/32.png) [@Rob\_Rogers1](https://community.cartalk.com/u/Rob_Rogers1)\ **Post date:** [April 14, 2020, 2:27am UTC](https://community.cartalk.com/t/98-toyota-camry-emissions-night-mare/162807/14 "2020-04-14T02:27:52Z")
yes has been replaced ---
**Author:** ![Honda-Blackbird](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/honda-blackbird/32/3159_2.png) [@Honda-Blackbird](https://community.cartalk.com/u/Honda-Blackbird)\ **Post date:** [April 14, 2020, 3:52am UTC](https://community.cartalk.com/t/98-toyota-camry-emissions-night-mare/162807/15 "2020-04-14T03:52:45Z")
Ok… i just hope you replaced it with a Toyota part. The VSV is one of those items that u need to use the oem part… at least this is what i was strongly advised… the aftermarket units seem to cause those 401/2’s to return So just a thought. Your issue isnt usually too difficult to solve as long as you go thru troubleshooting and verifying carefully… no skipped steps or assumptions… and im told… no aftermarket vsv in particular ---
**Author:** ![jdmere](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/jdmere/32/3002_2.png) [@jdmere](https://community.cartalk.com/u/jdmere)\ **Post date:** [April 14, 2020, 4:41am UTC](https://community.cartalk.com/t/98-toyota-camry-emissions-night-mare/162807/16 "2020-04-14T04:41:08Z")
Apologies. Never was good with math and the days are long. ---
**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\ **Post date:** [April 14, 2020, 3:51pm UTC](https://community.cartalk.com/t/98-toyota-camry-emissions-night-mare/162807/17 "2020-04-14T15:51:51Z")
Show me where I typed that your vehicle had a Delta Pressure Feedback EGR system? [https://www.toyotanation.com/threads/how-toyota-egr-vacuum-modulator-works-everything-you-need-to-know.1623818/](https://www.toyotanation.com/threads/how-toyota-egr-vacuum-modulator-works-everything-you-need-to-know.1623818/) Tester