2001 Toyota Corolla Logo
Posted on Jan 02, 2009
Answered by a Fixya Expert

Trustworthy Expert Solutions

At Fixya.com, our trusted experts are meticulously vetted and possess extensive experience in their respective fields. Backed by a community of knowledgeable professionals, our platform ensures that the solutions provided are thoroughly researched and validated.

View Our Top Experts

'99 Accord: P0420 and Sometimes Engine Hesitation & Rough Idling

Hey,

I have a '99 Honda Accord (4 cylinder VTEC) and I had a new gas tank fill-up last week. Ever since then, my car has started to hesistate when I try to accelerate, although it does this only occasionally. Moreover, sometimes my cars idle is rough, like the rpm nominally stays around 800 and it suddenly falls to 300 or so and recovers to 800 in 1 or 2 seconds.

A few days after all this, the check engine light came on with P0420 code (and its the only code). Although the code says that the catalytic converter efficiency is below threshold and something maybe wrong with it, I am not sure if a bad catalytic converter can cause my car to sometimes hesitate and exhibit rough idling.

Could P0420 appear if the gasoline I filled-up with was of poor quality?

I would honestly appreciate every advice from you.
Thank you!

2 Answers

Anonymous

Level 2:

An expert who has achieved level 2 by getting 100 points

MVP:

An expert that got 5 achievements.

Vice President:

An expert whose answer got voted for 100 times.

Sergeant:

An expert that has over 500 points.

  • Expert 184 Answers
  • Posted on Apr 15, 2009
Anonymous
Expert
Level 2:

An expert who has achieved level 2 by getting 100 points

MVP:

An expert that got 5 achievements.

Vice President:

An expert whose answer got voted for 100 times.

Sergeant:

An expert that has over 500 points.

Joined: Dec 12, 2008
Answers
184
Questions
0
Helped
218211
Points
661

If the converter is failed (i.e. plugged) it can cause drive-ability problems (i.e. the engine can't get the exhaust out like it normally can). FYI, http://p0420.com

Fix the known P0420 code first, then if the rough idle, etc continues, continue diagnosing. IMHO, don't worry about the MAF, etc. until you fix the "known" problems.

Anonymous

Level 1:

An expert who has achieved level 1.

  • Contributor 1 Answer
  • Posted on Mar 19, 2009
Anonymous
Contributor
Level 1:

An expert who has achieved level 1.

Joined: Mar 19, 2009
Answers
1
Questions
1
Helped
889
Points
1

First thing I would do is clean the throttle body if nothing changes check your mass air sensor if still nothing. change (or clean) your oxygen sensors can normally be found on the exhaust manifolds. also it couldn't hurt to give it an oil change and use a fuel additive to get rid off all the nasty build up in the engine I use BG 44K

That's all the information I have good luck!

Ad

Add Your Answer

×

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

0helpful
1answer

Whats the name of the wiring harness thats needed in a swap from non vtec to vtec

92-00 Honda Engine Swap Wiring Guide VTEC AND NON ...

honda-tech.com/.../92-00-honda-engine-swap-wiring-guide-vtec-non-vt...
Oct 8, 2011 - 92-00 Swap Wiring Guide for VTEC and Non-VTEC ... try to compile one thread that would try to answer pretty much 95% of all questions ... I wanted to do this because often times I end up posting the same thing to ... to ECU harness so using an EX/SI 92-95 engine harness will make VTEC plug and play.

97 accord non VTEC to VTEC ' HondaSwap

hondaswap.com > Model Specific > Accord
Jan 16, 2010 - 15 posts - ‎6 authors The distributors may be different on the vtec/non vtec. .... As was previously stated, allyou need to do is add wiring for VTEC. ... that connect to the ecu to the connectorsthat wire in your engine harness while the engine is out... f22b2 non vetec swap to f22b vtec need help asap
3 posts
Sep 22, 2012
96 accord head swap non vtec to vtec
10 posts
Jun 1, 2012
1990 USDM CRX Si D16A6 to ZC SOHC non-VTEC ...
20 posts
Mar 7, 2012
99 Accord non-vtec to vtec engine swap, need help
5 posts
Sep 27, 2011
More results from hondaswap.com
0helpful
2answers

Where is the fuel filter on a 99 honda accord lx

need to know if it is 4 or 6 cylinder
0helpful
1answer

My 1997 Honda accord ex,sometimes,after driving it awhile, it acts like it is running out of gas and studders.It only happens when I make a stop or wait for a traffic signal. Once,I accelerate it runs...

If you get rough idling or the tachometer needle does not stay in one place when idling then you may have a dirty or faulty idle air control valve. This is a common cause of the problem you are describing. Other issues could be dirty MAF sensor or loose wires or vacuum hose.
0helpful
1answer

I have a 97 honda accord se 4 cylinder non-vtec and here recently i have notice it has been eating up gas more than usual what could be the issue?

Assuming your check engine light isnt on, check for low tire pressure, a dirty air filter and check your oil level.
0helpful
1answer

Engine hesitation up until 45 mph. Rough engine idling, hard to accelerate

Could be the spark plugs! Run AC Delco the factory made these trucks to run best with this brand. Bad gas could cause a truck to run rough sometimes trash in the bottom of your gas tank from runnin' regular. Check your CAT convertor as well sometimes they become clogged and constrict airflow from goin' out the exhaust and back up what needs to escape from the engine. Your airfilter could be clogged as well. Hope this was helpful! Good luck
0helpful
1answer

Oil spec

1995 HONDA ACCORD 2.7L 6-cyl Engine Code C27A4 C27A1

Engine Oil Grade 1......API All TEMPS......5W-30
Manual Transmission,......SJ All TEMPS......10W-30, optional 10W-40
Automatic Transmission,MPZA......AF2

CAPACITIES:
Engine, with filter..........4.4 liters
Automatic Transmission, MPZA Initial Fill..........2.7 liters
Automatic Transmission, Total Fill
4 speed MPZA..........6 liters
Manual Transmission, ..........1.9 liters

1995 HONDA ACCORD 2.2L 4-cyl Engine Code F22B1 VTEC

Engine Oil Grade 1......API All TEMPS......5W-30
Manual Transmission,......SJ All TEMPS......10W-30, optional 10W-40
Automatic Transmission,A0YA......AF2

CAPACITIES:
Engine, with filter..........4.3 liters
Automatic Transmission, A0YA Initial Fill..........2.4 liters
Automatic Transmission, MP0A Initial Fill..........2.4 liters
Automatic Transmission, Total Fill
4 speed A0YA..........6 liters
4 speed MP0A..........6 liters
Manual Transmission, ..........1.9 liters

0helpful
1answer

P1259code 98 honda accord ex

p1259 is vtec system fail. check your oil level and condition. will prob need a vtec sol and filter and poss the vtec pressure switch.
0helpful
2answers

'99 Accord: P0420 and Sometimes Engine Hesitation & Rough Idling

You Definatelly got some Bad Fuel. Get a can of B-12 Chemtool from any Auto Parts Store or Wal-Mart and Pour it in the Gas Tank then Let it Run for a While. Should help Dramatically! Let me know!
Not finding what you are looking for?

899 views

Ask a Question

Usually answered in minutes!

Top Toyota Experts

ZJ Limited
ZJ Limited

Level 3 Expert

17989 Answers

Thomas Perkins
Thomas Perkins

Level 3 Expert

15088 Answers

ROBERT GARCIA
ROBERT GARCIA

Level 3 Expert

926 Answers

Are you a Toyota Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...